I know that The problem is quite easy, but I get WA and I don't know why

problem : https://icpcarchive.ecs.baylor.edu/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=4418

my Code : http://ideone.com/GRdOq5

I don't know whether my approach is wrong or I have a bug in my implementation or both :(