input:

3
3 3
1 3
2 3
1 2
12 6
2 3
5 7
1 9
4 8
1 2
7 11
4 5
3 4
2 3
1 2
4 4
1 1

output:

4

result:

wrong answer 1st numbers differ - expected: '1', found: '4'