Unexpected SIGABRT error on codechef

Why am i getting runtime error SIGABRT on this? http://ift.tt/2AMAOI8

To quote codechef, SIGABRT errors are caused by your program aborting due to a fatal error. In C++, this is normally due to an assert statement in C++ not returning true, but some STL elements can generate this if they try to store too much memory.