Input for test 1

5
1 3
5 2
4 3
3 5
Output for test 1

2
Input for test 2

7
1 2
1 5
2 3
3 4
5 6
6 7
Output for test 2

3
Input for test 3

30
1 8
1 18
28 8
21 8
23 1
28 26
21 5
18 3
18 19
3 15
23 12
14 3
28 30
21 10
9 15
17 19
19 4
10 27
6 26
6 11
9 16
15 22
10 24
9 25
17 20
2 12
13 1
4 29
7 26
Output for test 3

12

• Re:贴几组数据 (490) squarefk 2012-03-02 22:40:30