See some test cases below. I hope some of them will help you.
2 5
2 3 9 2 100
1 2 5 4 100
2 1
1 5
ans:
0

5 1
100000
0
1
100000
1
4 1
5 1
ans:
0

5 1
100000
0
1
100000
1
3 1
5 1
ans:
0

5 1
100000
0
1
1
1
4 1
5 1
ans:
100000

5 1
100000
1
1
1
1
4 1
5 1
ans:
99999

3 4
1 2 2 1
1 2 2 1
1 2 2 1
2 1
3 4
ans:
0

For WA16 these cases helped me:

4 6
1 1 1 2 2 2
2 2 2 3 3 3
4 4 4 4 4 4
4 5 5 5 5 4
2 2
3 1
ans:
-1

4 6
1 1 1 2 2 2
2 2 2 3 3 3
4 4 4 4 4 4
4 5 5 5 5 4
2 3
3 1
ans:
1

Thank you!