23 users have solved this problem:

testcoder, user, horiseun, he, lion, Edward, Owen24, Yuuron, ndosh, programmer123, WenDidIAsk, dorian, Philip_cpp, loctildore, numb3r5, Matthewwww, Double_Slash, pony_joe1, Gomango999, Lithanium, SirLemonMeringue, ralismark, Ghetto