Field Reduction

#1

http://usaco.org/index.php?page=viewproblem2&cpid=642

Edit: The input for a certain case is:
6
2 3
4 7
10 8
12 6
200 5
15 30

I know for a fact that the answer should be 40.

Shouldn’t the answer for this case be 16? We only need to use the cows at coordinates (4, 7), (10, 8), and (12, 6) and can remove the other 3 cows.

#2

Can someone explain why this arrangement of cows is incorrect?

#3

Which test case are you talking about? I can’t seem to find it in the test data.

#4

Nvm, figured it out.