MOD = 10 ** 9 + 7
N = int(input())
S = input()
dp = [[0, 0] for _ in range(10)]
dp[0][0] = 1
dic = dict(zip("yukicoder", range(1, 10)))
for s in S:
    if s in dic:
        a = dic[s]
        for i in range(2):
            dp[a][i] += dp[a - 1][i]
            dp[a][i] %= MOD
    if s == "?":
        for i in reversed(range(1, 10)):
            dp[i][1] += dp[i - 1][0]
            dp[i][1] %= MOD
print(sum(dp[-1]) % MOD)