73 users have solved this problem:

spdskatr, he, hmm789, evanl, iamnumber4, Gomango999, noblu, angeni, eddieee, yqqing, mohnishdeshpande, programmer123, dumpy, quanlin, warren_huang, horiseun, testcoder, user, lion, a_user, henryho2, Edward, hoangxuanbach, uylulu, tbinhnoob, binbau10, ntv2996, Yuuron, alexanyu, ndosh, Lvl9001Wizard, schua704, davinformatics, Yichen, Ghetto, loctildore, WenDidIAsk, yashb_9a3b, lupispuma74, dorian, Philip_cpp, xiaoxiong, ad_red, numb3r5, Matthewwww, Double_Slash, Sirhc_47, qwerty1, Uasoni2, Lucas4732, pony_joe1, Lithanium, Supermarine_Spitfire, jenny, OoogaDooga, PeaceOfCake, Zimo_Yoyo, Nosna, dusky, sssss, doantronganh2008, wap, Spectrum3563, trollkilung, dungbetele, freecoder_123, hienng, BuMiTa, Nhom9, PhanAnh628, emgalam118, orac, ifndef_INDEED_TIS_TRUE_HPP_