import sys
INF = float('inf')
#10**20,2**63,float('inf')
MOD = 10**9 + 7
MOD2 = 998244353
#from collections import defaultdict
def solve():
    def II(): return int(sys.stdin.readline())
    def LI(): return list(map(int, sys.stdin.readline().split()))
    def LC(): return list(input())
    def IC(): return [int(c) for c in input()]
    def MI(): return map(int, sys.stdin.readline().split())
    from collections import defaultdict
    Char = defaultdict(lambda:0)
    S = LC()
    for s in S:
        Char[s] +=1
    Tenkei = list("kyoprotenkei90")
    for t in Tenkei:
        Char[t]-=1
        if(Char[t]<0):
            print("No")
            exit()
    print("Yes")
    return
solve()
#sys.setrecursionlimit(10 ** 6)#再帰関数ではコメントにしないこと！！