51 users have solved this problem:

spdskatr, he, HSIENXIN, iamnumber4, testcoder, sidpark1, Lvl9001Wizard, Gomango999, Robeinstein, doublerun, dumpy, quanlin, evanl, hoangxuanbach, minhnhatnoe, binbau10, Yuuron, henryho2, warren_huang, jszqlew, clairesyd, UeliteEdu, xiaoxiong, inj, WenDidIAsk, davinformatics, lion, programmer123, dorian, Wilsonytan14, loctildore, Double_Slash, turtlecoder, Philip_cpp, Sirhc_47, Matthewwww, kidneythedolphin, DumplingLife, No2Banker, jmuzhen, Ghetto, Uasoni2, aerobull42, pony_joe1, caterpillow, Lucas4732, Lithanium, dusky, PeaceOfCake, OoogaDooga, Supermarine_Spitfire