Codeforces Round #409 (rated, Div. 2, based on VK Cup 2017 Round 2) A -- D
A.ViciousKeyboardtimelimitpertest2secondsmemorylimitpertest256megabytesinputstandardinputoutputstandardoutputToniohasakeyboardwithonlytwoletters,"V"and"K".Oneday,hehastypedoutastringswithonlythesetwol