Given two strings of lowercase letters and . Print the longest string that is simultaneously a substring of the permutation of and a substring of the permutation of .
Consists of multiple test cases, each contains a pair of lines. The first line of a pair contains and the second line contains . Each string is on a separate line and consists of at most lowercase letters.
For each subsequent pair of input lines print a line containing . If several satisfy the criteria above, choose the first one in alphabetical order.