N=int(input())
S=input()

Mod=10**9+7
yukicoder=set("yukicoder")
Ind={a:i for i,a in enumerate("yukicoder")}

DP=[[0,0] for _ in range(10)]
DP[0][0]=1

for s in S:
    E=DP
    DP=[[0,0] for _ in range(10)]

    for level in range(10):
        for mode in [0,1]:
            DP[level][mode]=E[level][mode]

    if s=="?":
        for level in range(9):
            DP[level+1][1]+=DP[level][0]
    elif s in yukicoder:
        level=Ind[s]
        DP[level+1][0]+=DP[level][0]
        DP[level+1][1]+=DP[level][1]


    for level in range(10):
        DP[level][0]%=Mod
        DP[level][1]%=Mod

print(sum(DP[9])%Mod)