18 users have solved this problem:

Double_Slash, Lithanium, Nonoze, ludissey, Amelon, finehaveanormalusername, caterpillow, evanl, dusky, grossly_overconfident, Pumkinhead, icaijy, HelperTcell, liangjeremy, Nick_Cpp, Chez, WenDidIAsk, qiqicoder,