To get better at Golang, I decided to try solving Codeforces (CF) problems in Go. I was a bit surprised that the current Go version on CF is (out-of-dated) 1.2, while the current stable Go version is 1.5.
Having said that, my solution for this C div 2 produced correct answers for the given two sample testcases on my computer (with Go 1.5), but gave wrong answers on CF. I've looked at the issue for a while, but could not understand the cause. Could anyone give me some hint?

By the way, is there any plan to update the Go version on Codeforces? I'm not sure who (Mike Mirzayanov?) I should ask for this, though.