31 users have solved this problem:

programmer123, evanl, he, lion, Gomango999, dumpy, Netanya, user, testcoder, phoebe, Magikarp4000, SirLemonMeringue, horiseun, dorian, Philip_cpp, pony_joe1, RonXueAlt, Matthewwww, ralismark, Lithanium, Double_Slash, caterpillow, Uasoni2, ar88lo, davinformatics, OneT_Chen, anson, aerobull42, WenDidIAsk, jtia8705, blx330