Problems

# Common permutation

# Common permutation

Given two strings of lowercase letters **a** and **b**. Print the longest string **x** that simultaneously is a substring of permutation of **a** and is a substring of permutation of **b**.

#### Input

Input consists of pairs of lines. The first line of a pair contains **a** and the second contains **b**. Each string is on a separate line and consists of at most **1000** lowercase letters.

#### Output

For each subsequent pair of input lines print a line containing **x**. If several **x** satisfy the criteria above, choose the first one in alphabetical order.

Input example #1

pretty women walking down the street

Output example #1

e nw et