#Write a piped command using head, tail, sort, cut, and sed to return the date of the latest event in the file in yyyy/mm/dd format

Input file:

date time protocol ip-address port packet-size

2018-01-01 19:27:19 TCP 11.101.6.64 22 44

2018-04-17 01:35:12 UDP 10.101.7.69 2135 83

2018-05-05 04:26:05 UDP 11.101.6.65 2160 104

2018-08-20 15:43:16 TCP 10.101.7.64 22 113

2018-02-10 02:28:02 UDP 11.101.6.65 2089 68

2018-03-22 00:05:32 TCP 9.101.7.65 23 92

2018-04-24 19:32:47 TCP 9.100.8.65 22 93

2018-05-19 01:22:06 TCP 10.100.7.64 2107 29

2018-04-13 03:51:33 TCP 9.102.8.64 22 32

2018-08-16 21:02:36 UDP 11.100.8.65 2190 17

2018-06-27 00:44:54 UDP 11.101.6.65 2109 73

2018-01-08 07:39:00 TCP 10.101.8.65 22 74

2018-01-22 07:08:54 UDP 9.101.7.65 2165 27

2018-01-11 07:17:44 TCP 11.101.6.65 22 110

2018-01-10 13:14:41 TCP 10.101.7.64 22 89

2018-08-23 13:47:24 UDP 11.100.6.65 2187 93

2018-08-17 06:29:35 TCP 11.101.6.65 2114 66

2018-11-23 02:22:22 UDP 9.100.7.64 2142 118

2018-09-22 22:06:47 TCP 11.101.6.65 22 9

2018-04-04 09:41:43 UDP 9.102.7.64 2116 34

Output expected:

2018/11/23