Here are some tests:

5 6
1 1
1 2
Answer: 1

5 6
1 2
2 6
Answer: 5

5 6
1 5
2 6
Answer: 2

5 6
1 5
1 2
Answer: 3 (Here I think you may have WA, because second point occur first)

5 6
2 3
3 3
Answer: 9

Good Luck!!!

My prog passes all of this test but still wa4.why?

Test 4 contains (1,1) as second point imho.