[0] 0.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 1.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 2.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 3.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 4.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 5.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 6.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 7.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 8.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 9.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 10.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 11.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 12.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 13.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 14.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 15.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 16.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 17.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 18.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 19.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 20.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 21.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 22.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 23.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 24.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 25.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 26.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 27.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 28.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 29.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 30.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 31.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[86400] 32.201.172.210.in-addr.arpa. domain name pointer p201032.mirai.ne.jp
[86400] 33.201.172.210.in-addr.arpa. domain name pointer HW-A-ge104.mirai.ad.jp
[86400] 34.201.172.210.in-addr.arpa. domain name pointer p201034.mirai.ne.jp
[86400] 35.201.172.210.in-addr.arpa. domain name pointer p201035.mirai.ne.jp
[86400] 36.201.172.210.in-addr.arpa. domain name pointer p201036.mirai.ne.jp
[86400] 37.201.172.210.in-addr.arpa. domain name pointer HW-A-ge104.mirai.ad.jp
[86400] 38.201.172.210.in-addr.arpa. domain name pointer p201038.mirai.ne.jp
[86400] 39.201.172.210.in-addr.arpa. domain name pointer p201039.mirai.ne.jp
[86400] 40.201.172.210.in-addr.arpa. domain name pointer p201040.mirai.ne.jp
[86400] 41.201.172.210.in-addr.arpa. domain name pointer HW-A-ge104.mirai.ad.jp
[86400] 42.201.172.210.in-addr.arpa. domain name pointer p201042.mirai.ne.jp
[86400] 43.201.172.210.in-addr.arpa. domain name pointer p201043.mirai.ne.jp
[86400] 44.201.172.210.in-addr.arpa. domain name pointer p201044.mirai.ne.jp
[86400] 45.201.172.210.in-addr.arpa. domain name pointer HW-A-ge104.mirai.ad.jp
[86400] 46.201.172.210.in-addr.arpa. domain name pointer p201046.mirai.ne.jp
[86400] 47.201.172.210.in-addr.arpa. domain name pointer p201047.mirai.ne.jp
[0] 48.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 49.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 50.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 51.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 52.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 53.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 54.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 55.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 56.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 57.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 58.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 59.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 60.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 61.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 62.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 63.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[86400] 64.201.172.210.in-addr.arpa. domain name pointer p201064.mirai.ne.jp
[86400] 65.201.172.210.in-addr.arpa. domain name pointer HW-A-ge104.mirai.ad.jp
[86400] 66.201.172.210.in-addr.arpa. domain name pointer p201066.mirai.ne.jp
[86400] 67.201.172.210.in-addr.arpa. domain name pointer p201067.mirai.ne.jp
[86400] 68.201.172.210.in-addr.arpa. domain name pointer p201068.mirai.ne.jp
[86400] 69.201.172.210.in-addr.arpa. domain name pointer p201069.mirai.ne.jp
[86400] 70.201.172.210.in-addr.arpa. domain name pointer p201070.mirai.ne.jp
[86400] 71.201.172.210.in-addr.arpa. domain name pointer p201071.mirai.ne.jp
[86400] 72.201.172.210.in-addr.arpa. domain name pointer p201072.mirai.ne.jp
[86400] 73.201.172.210.in-addr.arpa. domain name pointer kmksys.kmk-gifu.jp
[86400] 74.201.172.210.in-addr.arpa. domain name pointer p201074.mirai.ne.jp
[86400] 75.201.172.210.in-addr.arpa. domain name pointer p201075.mirai.ne.jp
[86400] 76.201.172.210.in-addr.arpa. domain name pointer p201076.mirai.ne.jp
[86400] 77.201.172.210.in-addr.arpa. domain name pointer p201077.mirai.ne.jp
[86400] 78.201.172.210.in-addr.arpa. domain name pointer p201078.mirai.ne.jp
[86400] 79.201.172.210.in-addr.arpa. domain name pointer p201079.mirai.ne.jp
[86400] 80.201.172.210.in-addr.arpa. domain name pointer p201080.mirai.ne.jp
[86400] 81.201.172.210.in-addr.arpa. domain name pointer p201081.mirai.ne.jp
[86400] 82.201.172.210.in-addr.arpa. domain name pointer p201082.mirai.ne.jp
[86400] 83.201.172.210.in-addr.arpa. domain name pointer p201083.mirai.ne.jp
[86400] 84.201.172.210.in-addr.arpa. domain name pointer p201084.mirai.ne.jp
[86400] 85.201.172.210.in-addr.arpa. domain name pointer p201085.mirai.ne.jp
[86400] 86.201.172.210.in-addr.arpa. domain name pointer p201086.mirai.ne.jp
[86400] 87.201.172.210.in-addr.arpa. domain name pointer p201087.mirai.ne.jp
[86400] 88.201.172.210.in-addr.arpa. domain name pointer p201088.mirai.ne.jp
[86400] 89.201.172.210.in-addr.arpa. domain name pointer HW-A-ge104.mirai.ad.jp
[86400] 90.201.172.210.in-addr.arpa. domain name pointer p201090.mirai.ne.jp
[86400] 91.201.172.210.in-addr.arpa. domain name pointer p201091.mirai.ne.jp
[86400] 92.201.172.210.in-addr.arpa. domain name pointer p201092.mirai.ne.jp
[86400] 93.201.172.210.in-addr.arpa. domain name pointer p201093.mirai.ne.jp
[86400] 94.201.172.210.in-addr.arpa. domain name pointer p201094.mirai.ne.jp
[86400] 95.201.172.210.in-addr.arpa. domain name pointer p201095.mirai.ne.jp
[86400] 96.201.172.210.in-addr.arpa. domain name pointer p201096.mirai.ne.jp
[86400] 97.201.172.210.in-addr.arpa. domain name pointer HW-A-ge104.mirai.ad.jp
[86400] 98.201.172.210.in-addr.arpa. domain name pointer p201098.mirai.ne.jp
[86400] 99.201.172.210.in-addr.arpa. domain name pointer p201099.mirai.ne.jp
[86400] 100.201.172.210.in-addr.arpa. domain name pointer p201100.mirai.ne.jp
[86400] 101.201.172.210.in-addr.arpa. domain name pointer p201101.mirai.ne.jp
[86400] 102.201.172.210.in-addr.arpa. domain name pointer p201102.mirai.ne.jp
[86400] 103.201.172.210.in-addr.arpa. domain name pointer p201103.mirai.ne.jp
[86400] 104.201.172.210.in-addr.arpa. domain name pointer p201104.mirai.ne.jp
[86400] 105.201.172.210.in-addr.arpa. domain name pointer p201105.mirai.ne.jp
[86400] 106.201.172.210.in-addr.arpa. domain name pointer p201106.mirai.ne.jp
[86400] 107.201.172.210.in-addr.arpa. domain name pointer p201107.mirai.ne.jp
[86400] 108.201.172.210.in-addr.arpa. domain name pointer p201108.mirai.ne.jp
[86400] 109.201.172.210.in-addr.arpa. domain name pointer p201109.mirai.ne.jp
[86400] 110.201.172.210.in-addr.arpa. domain name pointer p201110.mirai.ne.jp
[86400] 111.201.172.210.in-addr.arpa. domain name pointer p201111.mirai.ne.jp
[0] 112.201.172.210.in-addr.arpa.: domain name does not exist
[0] 113.201.172.210.in-addr.arpa.: domain name does not exist
[0] 114.201.172.210.in-addr.arpa.: domain name does not exist
[0] 115.201.172.210.in-addr.arpa.: domain name does not exist
[86400] 116.201.172.210.in-addr.arpa. domain name pointer exdns02.gifu-cn.ac.jp
[86400] 117.201.172.210.in-addr.arpa. domain name pointer libweb01.gifu-cn.ac.jp
[86400] 118.201.172.210.in-addr.arpa. domain name pointer areaweb01.gifu-cn.ac.jp
[86400] 119.201.172.210.in-addr.arpa. domain name pointer graduate.gifu-cn.ac.jp
[86400] 120.201.172.210.in-addr.arpa. domain name pointer notes01.gifu-cn.ac.jp
[86400] 121.201.172.210.in-addr.arpa. domain name pointer areaweb02.gifu-cn.ac.jp
[86400] 122.201.172.210.in-addr.arpa. domain name pointer gate01.gifu-cn.ac.jp
[86400] 123.201.172.210.in-addr.arpa. domain name pointer gate02.gifu-cn.ac.jp
[86400] 124.201.172.210.in-addr.arpa. domain name pointer wm.gifu-cn.ac.jp
[0] 125.201.172.210.in-addr.arpa.: domain name does not exist
[0] 126.201.172.210.in-addr.arpa.: domain name does not exist
[0] 127.201.172.210.in-addr.arpa.: domain name does not exist
[86400] 128.201.172.210.in-addr.arpa. domain name pointer p201128.mirai.ne.jp
[86400] 129.201.172.210.in-addr.arpa. domain name pointer HW-A-ge104.mirai.ad.jp
[86400] 130.201.172.210.in-addr.arpa. domain name pointer p201130.mirai.ne.jp
[86400] 131.201.172.210.in-addr.arpa. domain name pointer p201131.mirai.ne.jp
[86400] 132.201.172.210.in-addr.arpa. domain name pointer p201132.mirai.ne.jp
[86400] 133.201.172.210.in-addr.arpa. domain name pointer p201133.mirai.ne.jp
[86400] 134.201.172.210.in-addr.arpa. domain name pointer p201134.mirai.ne.jp
[86400] 135.201.172.210.in-addr.arpa. domain name pointer p201135.mirai.ne.jp
[86400] 136.201.172.210.in-addr.arpa. domain name pointer p201136.mirai.ne.jp
[86400] 137.201.172.210.in-addr.arpa. domain name pointer p201137.mirai.ne.jp
[86400] 138.201.172.210.in-addr.arpa. domain name pointer p201138.mirai.ne.jp
[86400] 139.201.172.210.in-addr.arpa. domain name pointer p201139.mirai.ne.jp
[86400] 140.201.172.210.in-addr.arpa. domain name pointer p201140.mirai.ne.jp
[86400] 141.201.172.210.in-addr.arpa. domain name pointer p201141.mirai.ne.jp
[86400] 142.201.172.210.in-addr.arpa. domain name pointer p201142.mirai.ne.jp
[86400] 143.201.172.210.in-addr.arpa. domain name pointer p201143.mirai.ne.jp
[86400] 144.201.172.210.in-addr.arpa. domain name pointer p201144.mirai.ne.jp
[86400] 145.201.172.210.in-addr.arpa. domain name pointer HW-A-ge104.mirai.ad.jp
[86400] 146.201.172.210.in-addr.arpa. domain name pointer p201146.mirai.ne.jp
[86400] 147.201.172.210.in-addr.arpa. domain name pointer p201147.mirai.ne.jp
[86400] 148.201.172.210.in-addr.arpa. domain name pointer p201148.mirai.ne.jp
[86400] 149.201.172.210.in-addr.arpa. domain name pointer p201149.mirai.ne.jp
[86400] 150.201.172.210.in-addr.arpa. domain name pointer p201150.mirai.ne.jp
[86400] 151.201.172.210.in-addr.arpa. domain name pointer p201151.mirai.ne.jp
[86400] 152.201.172.210.in-addr.arpa. domain name pointer p201152.mirai.ne.jp
[86400] 153.201.172.210.in-addr.arpa. domain name pointer HW-A-ge104.mirai.ad.jp
[86400] 154.201.172.210.in-addr.arpa. domain name pointer p201154.mirai.ne.jp
[86400] 155.201.172.210.in-addr.arpa. domain name pointer p201155.mirai.ne.jp
[86400] 156.201.172.210.in-addr.arpa. domain name pointer p201156.mirai.ne.jp
[86400] 157.201.172.210.in-addr.arpa. domain name pointer p201157.mirai.ne.jp
[86400] 158.201.172.210.in-addr.arpa. domain name pointer p201158.mirai.ne.jp
[86400] 159.201.172.210.in-addr.arpa. domain name pointer p201159.mirai.ne.jp
[0] 160.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 161.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 162.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 163.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 164.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 165.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 166.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 167.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 168.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 169.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 170.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 171.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 172.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 173.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 174.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[0] 175.201.172.210.in-addr.arpa.: valid domain but no data of requested type
[86400] 176.201.172.210.in-addr.arpa. domain name pointer p201176.mirai.ne.jp
[86400] 177.201.172.210.in-addr.arpa. domain name pointer HW-A-ge104.mirai.ad.jp
[86400] 178.201.172.210.in-addr.arpa. domain name pointer p201178.mirai.ne.jp
[86400] 179.201.172.210.in-addr.arpa. domain name pointer p201179.mirai.ne.jp
[86400] 180.201.172.210.in-addr.arpa. domain name pointer p201180.mirai.ne.jp
[86400] 181.201.172.210.in-addr.arpa. domain name pointer p201181.mirai.ne.jp
[86400] 182.201.172.210.in-addr.arpa. domain name pointer p201182.mirai.ne.jp
[86400] 183.201.172.210.in-addr.arpa. domain name pointer p201183.mirai.ne.jp
[86400] 184.201.172.210.in-addr.arpa. domain name pointer p201184.mirai.ne.jp
[86400] 185.201.172.210.in-addr.arpa. domain name pointer p201185.mirai.ne.jp
[86400] 186.201.172.210.in-addr.arpa. domain name pointer p201186.mirai.ne.jp
[86400] 187.201.172.210.in-addr.arpa. domain name pointer p201187.mirai.ne.jp
[86400] 188.201.172.210.in-addr.arpa. domain name pointer p201188.mirai.ne.jp
[86400] 189.201.172.210.in-addr.arpa. domain name pointer p201189.mirai.ne.jp
[86400] 190.201.172.210.in-addr.arpa. domain name pointer p201190.mirai.ne.jp
[86400] 191.201.172.210.in-addr.arpa. domain name pointer p201191.mirai.ne.jp
[86400] 192.201.172.210.in-addr.arpa. domain name pointer p201192.mirai.ne.jp
[86400] 193.201.172.210.in-addr.arpa. domain name pointer HW-A-ge104.mirai.ad.jp
[86400] 194.201.172.210.in-addr.arpa. domain name pointer p201194.mirai.ne.jp
[86400] 195.201.172.210.in-addr.arpa. domain name pointer p201195.mirai.ne.jp
[86400] 196.201.172.210.in-addr.arpa. domain name pointer p201196.mirai.ne.jp
[86400] 197.201.172.210.in-addr.arpa. domain name pointer p201197.mirai.ne.jp
[86400] 198.201.172.210.in-addr.arpa. domain name pointer p201198.mirai.ne.jp
[86400] 199.201.172.210.in-addr.arpa. domain name pointer p201199.mirai.ne.jp
[86400] 200.201.172.210.in-addr.arpa. domain name pointer p201200.mirai.ne.jp
[86400] 201.201.172.210.in-addr.arpa. domain name pointer p201201.mirai.ne.jp
[86400] 202.201.172.210.in-addr.arpa. domain name pointer p201202.mirai.ne.jp
[86400] 203.201.172.210.in-addr.arpa. domain name pointer p201203.mirai.ne.jp
[86400] 204.201.172.210.in-addr.arpa. domain name pointer p201204.mirai.ne.jp
[86400] 205.201.172.210.in-addr.arpa. domain name pointer p201205.mirai.ne.jp
[86400] 206.201.172.210.in-addr.arpa. domain name pointer p201206.mirai.ne.jp
[86400] 207.201.172.210.in-addr.arpa. domain name pointer p201207.mirai.ne.jp
[86400] 208.201.172.210.in-addr.arpa. domain name pointer p201208.mirai.ne.jp
[86400] 209.201.172.210.in-addr.arpa. domain name pointer p201209.mirai.ne.jp
[86400] 210.201.172.210.in-addr.arpa. domain name pointer p201210.mirai.ne.jp
[86400] 211.201.172.210.in-addr.arpa. domain name pointer p201211.mirai.ne.jp
[86400] 212.201.172.210.in-addr.arpa. domain name pointer p201212.mirai.ne.jp
[86400] 213.201.172.210.in-addr.arpa. domain name pointer p201213.mirai.ne.jp
[86400] 214.201.172.210.in-addr.arpa. domain name pointer p201214.mirai.ne.jp
[86400] 215.201.172.210.in-addr.arpa. domain name pointer p201215.mirai.ne.jp
[86400] 216.201.172.210.in-addr.arpa. domain name pointer p201216.mirai.ne.jp
[86400] 217.201.172.210.in-addr.arpa. domain name pointer p201217.mirai.ne.jp
[86400] 218.201.172.210.in-addr.arpa. domain name pointer p201218.mirai.ne.jp
[86400] 219.201.172.210.in-addr.arpa. domain name pointer p201219.mirai.ne.jp
[86400] 220.201.172.210.in-addr.arpa. domain name pointer p201220.mirai.ne.jp
[86400] 221.201.172.210.in-addr.arpa. domain name pointer p201221.mirai.ne.jp
[86400] 222.201.172.210.in-addr.arpa. domain name pointer p201222.mirai.ne.jp
[86400] 223.201.172.210.in-addr.arpa. domain name pointer p201223.mirai.ne.jp
[86400] 224.201.172.210.in-addr.arpa. domain name pointer p201224.mirai.ne.jp
[86400] 225.201.172.210.in-addr.arpa. domain name pointer HW-A-ge104.mirai.ad.jp
[86400] 226.201.172.210.in-addr.arpa. domain name pointer p201226.mirai.ne.jp
[86400] 227.201.172.210.in-addr.arpa. domain name pointer p201227.mirai.ne.jp
[86400] 228.201.172.210.in-addr.arpa. domain name pointer p201228.mirai.ne.jp
[86400] 229.201.172.210.in-addr.arpa. domain name pointer p201229.mirai.ne.jp
[86400] 230.201.172.210.in-addr.arpa. domain name pointer p201230.mirai.ne.jp
[86400] 231.201.172.210.in-addr.arpa. domain name pointer p201231.mirai.ne.jp
[86400] 232.201.172.210.in-addr.arpa. domain name pointer p201232.mirai.ne.jp
[86400] 233.201.172.210.in-addr.arpa. domain name pointer p201233.mirai.ne.jp
[86400] 234.201.172.210.in-addr.arpa. domain name pointer p201234.mirai.ne.jp
[86400] 235.201.172.210.in-addr.arpa. domain name pointer p201235.mirai.ne.jp
[86400] 236.201.172.210.in-addr.arpa. domain name pointer p201236.mirai.ne.jp
[86400] 237.201.172.210.in-addr.arpa. domain name pointer p201237.mirai.ne.jp
[86400] 238.201.172.210.in-addr.arpa. domain name pointer p201238.mirai.ne.jp
[86400] 239.201.172.210.in-addr.arpa. domain name pointer p201239.mirai.ne.jp
[86400] 240.201.172.210.in-addr.arpa. domain name pointer p201240.mirai.ne.jp
[86400] 241.201.172.210.in-addr.arpa. domain name pointer p201241.mirai.ne.jp
[86400] 242.201.172.210.in-addr.arpa. domain name pointer p201242.mirai.ne.jp
[86400] 243.201.172.210.in-addr.arpa. domain name pointer p201243.mirai.ne.jp
[86400] 244.201.172.210.in-addr.arpa. domain name pointer p201244.mirai.ne.jp
[86400] 245.201.172.210.in-addr.arpa. domain name pointer p201245.mirai.ne.jp
[86400] 246.201.172.210.in-addr.arpa. domain name pointer p201246.mirai.ne.jp
[86400] 247.201.172.210.in-addr.arpa. domain name pointer p201247.mirai.ne.jp
[86400] 248.201.172.210.in-addr.arpa. domain name pointer p201248.mirai.ne.jp
[86400] 249.201.172.210.in-addr.arpa. domain name pointer p201249.mirai.ne.jp
[86400] 250.201.172.210.in-addr.arpa. domain name pointer p201250.mirai.ne.jp
[86400] 251.201.172.210.in-addr.arpa. domain name pointer p201251.mirai.ne.jp
[86400] 252.201.172.210.in-addr.arpa. domain name pointer p201252.mirai.ne.jp
[86400] 253.201.172.210.in-addr.arpa. domain name pointer p201253.mirai.ne.jp
[86400] 254.201.172.210.in-addr.arpa. domain name pointer p201254.mirai.ne.jp
[0] 255.201.172.210.in-addr.arpa.: domain name does not exist