MOD = 10 ** 9 + 7

n = int(input())
S = input()
lst = ["yukicoder"]
yu = "yukicoder"
for i in range(9):
    t = yu[:i] + "?" + yu[i + 1:]
    lst.append(t)
    
ans = 0
for t in lst:
    dp = [0] * 10
    dp[0] = 1
    for s in S:
        for i in range(8, -1, -1):
            if t[i] == s:
                dp[i + 1] += dp[i]
                dp[i + 1] %= MOD
    ans += dp[-1]
    ans %= MOD

print(ans)