Input an integer N in the first line of each sets of test data.
Output N numbers in the second line .The next K lines, each line output two integers Ai and Bi, said Ai this number is present Bi.
5
5 5 2 2 1
6
1 9 9 2 3 0
3
1 1
2 2
5 2
5
0 1
1 1
2 1
3 1
9 2