input:

20 19
4 2
12 15
18 3
11 8
16 15
13 19
7 11
6 3
8 15
1 13
5 11
10 6
6 14
1 3
13 2
9 2
8 1
17 19
19 20

output:

1 0
13 1
19 13
17 19
20 19
2 13
4 2
9 2
3 1
18 3
6 3
10 6
14 6
8 1
11 8
7 11
5 11
15 8
12 15
16 15
1 19 17 20 2 4 9 13 18 6 10 14 3 11 7 5 15 12 16 8 

result:

wrong answer Integer 0 violates the range [1, 20]