dic = {"k": 0, "a": 0, "d": 0, "o": 0, "m": 0, "t": 0, "s":0, "u": 0}

S = input()
for s in S:
    if s in dic:
        dic[s] += 1
    else:
        dic[s] = 1

z = sum(v == 0 for v in dic.values())
a = sum(v == 0 for v in dic.values())

if z > 1 or a > 3:
    print("No")
else:
    print("Yes")