mod = 1000000007
eps = 10**-9


def main():
    import sys
    input = sys.stdin.readline

    N = int(input())
    S = input().rstrip('\n')
    T = "yukicoder"

    dp = [[0] * (N+1) for _ in range(19)]
    dp[0][0] = 1
    for i, s in enumerate(S):
        for state in range(19):
            if state < 9:
                if s == T[state]:
                    dp[state + 1][i+1] = (dp[state + 1][i+1] + dp[state][i])%mod
                elif s == "?":
                    dp[state + 10][i+1] = (dp[state + 10][i+1] + dp[state][i])%mod

                dp[state][i+1] = (dp[state][i+1] + dp[state][i])%mod
            elif 10 <= state < 18:
                if s == T[state - 9]:
                    dp[state + 1][i+1] = (dp[state + 1][i+1] + dp[state][i])%mod
                dp[state][i + 1] = (dp[state][i + 1] + dp[state][i]) % mod
            else:
                dp[state][i + 1] = (dp[state][i + 1] + dp[state][i]) % mod
    print((dp[-1][-1] + dp[9][-1])%mod)


if __name__ == '__main__':
    main()