I solved D-Lakes in Berland(Round #375 Div2) in the contest and I got Accepted,

Link : http://mirror.codeforces.com/contest/723/problem/D

My submission : http://mirror.codeforces.com/contest/723/submission/21161297

However after the contest I found a counter test that my code gets wrong , here it is :

http://imgur.com/a/tnXeT

the output should be 2304 (changes) instead the output is 0 ,

the problem is that I was looping from 1 to 500 instead of 2500 .

is the test right ? is there a bug in the system test ?