You have found the Elves here.
Elves don't like to be found. So, they change the way they live in string. Elves live in two strings. The longgest common substring is the elf.
e.g. in 12345abcde and 9876545a23124 "45a" is the longgest common substring. This is the elf.
There are mulitple test cases.
Each test case contain two strings in one row. (the lenght of string <= 100, the lenght of elf > 2)
For each test case, find the elf and print out in one row.
12345abcde 9876545a32164 abcdefg poicdefaf3