56 users have solved this problem:

pmoore, programmer123, evanl, he, Bean, dumpy, Netanya, brchen, uylulu, lion, alexanyu, Gomango999, user, testcoder, SirLemonMeringue, phoebe, ndosh, loctildore, dorian, Philip_cpp, harrysun2006, davinformatics, WenDidIAsk, BigD, Double_Slash, Matthewwww, Magikarp4000, Ghetto, pony_joe1, JerryTheBerry, Nosna, AlphaTao, Supermarine_Spitfire, OoogaDooga, Andy, PeaceOfCake, ralismark, Lithanium, anson, warren_huang, BurwoodChenFamily, aerobull42, Uasoni2, awu, finehaveanormalusername, dusky, caterpillow, jenny, orac, OneT_Chen, blx330, ar88lo, chchn2507, Vedang, PythonSweat, Philip_C