N = int(input())
S = input()
MOD = 10**9+7
T = 'yukicoder'
U = set(list(T))
dp = [[0]*3 for _ in range(10)]
dp[0][0] = 1

for s in S:
    if s == '?':
        for i in range(9, 0, -1):
            dp[i][1] += dp[i-1][0]
            dp[i][1] %= MOD
    elif s in U:
        i = T.index(s)
        dp[i+1][0] += dp[i][0]
        dp[i+1][0] %= MOD
        dp[i+1][2] += dp[i][1]+dp[i][2]
        dp[i+1][2] %= MOD

print(sum(dp[-1]) % MOD)