Sanitize Pair List

Given a list of integer pairs, remove the pairs where both numbers are equal. In mathematical terms, for each pair ((a, b)), only output the pair if (a \neq b). The relative order of the original pairs must be preserved.

inputFormat

The input is read from standard input. The first line contains an integer (n), which represents the number of pairs. Each of the following (n) lines contains two space-separated integers representing a pair ((a, b)).

outputFormat

For every pair ((a, b)) with (a \neq b), print the pair on a separate line as two space-separated integers. If no valid pair exists, output nothing.## sample

3
1 1
2 2
3 3