제출 #189299

6 7
3 5
4 6
2 3
1 5
5 2
6 5
3 1
0 0

Case 1: A forest of -1 trees.

Case 1: No trees.

4 5
4 2
1 3
1 4
2 3
3 4
8 1
6 5
0 0

Case 1: A forest of -1 trees.
Case 2: A forest of 7 trees.

Case 1: No trees.
Case 2: A forest of 7 trees.

5 5
4 3
1 4
2 3
3 1
4 2
3 1
2 1
7 6
3 2
5 7
6 5
2 4
6 7
4 3
6 1
1 2
0 0

Case 1: No trees.
Case 2: A forest of 2 trees.
Case 3: There is one tree.
Case 4: A forest of 5 trees.

Case 1: There is one tree.
Case 2: A forest of 2 trees.
Case 3: There is one tree.
Case 4: A forest of 5 trees.