"""

"""
from sys import stdin
import sys

yuki = "yukicoder"

N = int(stdin.readline())

S = stdin.readline()[:-1]

dp = [ [0] * 2 for i in range(len(yuki)+1)]
dp[0][0] = 1

mod = 10**9+7

for i in range(N):

    ndp = [ [dp[a][j] for j in range(2)]  for a in range(len(yuki)+1)]

    for a in range(len(yuki)):
        for b in range(2):

            if yuki[a] == S[i]:
                ndp[a+1][b] += dp[a][b]
                ndp[a+1][b] %= mod
            elif b == 0 and S[i] == "?":
                ndp[a+1][1] += dp[a][0]
                ndp[a+1][1] %= mod

    dp = ndp

ans = 0
for i in range(2):
    ans += dp[-1][i]
print (ans % mod)