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

Please help

5 5
5 1 10 1 1
10 1 1 1 1
1 1 1 1 1
1 1 1 1 1
1 1 1 1 1
2 2
1 3
Ans: 9

5 5
10 8 8 7 6
8 8 7 6 5
8 7 6 5 4
7 6 5 4 3
6 5 4 3 4
2 2
1 2
Ans: 1

5 5
10 8 8 7 6
8 8 7 6 5
8 7 6 5 4
7 6 5 4 3
6 5 4 3 7
2 2
1 2
Ans: 2

3 3
1 1 1
1 1 1
1 1 10
1 1
2 2
Ans: -1

5 5
1 10 25  30 35
50 1 24  30 35
1 10 23  30 35
10 50 22 30 35
1 39 21  30 39
1 1
1 5
Ans: 9

Ho to fix WA on test 18?

If you have WA #5 try below test:
2 5
2 3 9 2 100
1 2 5 4 100
2 1
1 5

Correct answer is 0.