I am trying to solve problem https://codeforces.com/contest/372/problem/A .
This is my sourcecode: http://cpp.sh/3rqwk. My codeforces submission is here: https://codeforces.com/contest/372/submission/55705312.
My code runs on my computer and cpp.sh on the two examples successfully but gets "Runtime Error" with a huge descrpition on the site. I know how volatile the are multiset erase operations, but I can't figure out why it won't run specifically on codeforces.