First Non-Repeating Character

Given a string S, find the first character that does not repeat. If all characters repeat, output an underscore _.

For example, in the string swiss, the first non-repeating character is w.

The solution requires reading multiple test cases from standard input and processing each string independently.

Note: If there is no character that appears only once, output _.

inputFormat

The first line of input contains an integer T representing the number of test cases. Each of the following T lines contains a string S.

Input is read from standard input (stdin).

outputFormat

For each test case, print a single line with the first non-repeating character of the string S. If no such character exists, print an underscore _.

Output is written to standard output (stdout).

## sample

3
swiss
hello
aabbcc

w
h
_

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