n = int(input())
S = input()
dp = [[0]*2 for i in range(10)]
dp[0][0] = 1
mod = 10**9+7
t = list("yukicoder")
for s in S:
    if s not in t and s != "?":
        continue
    
    for j in range(9)[::-1]:
        if s == t[j]:
            dp[j+1][0] += dp[j][0]
            dp[j+1][1] += dp[j][1]
            dp[j+1][0] %= mod
            dp[j+1][1] %= mod
        if s == "?":
            dp[j+1][1] += dp[j][0]
            dp[j+1][1] %= mod
print(sum(dp[-1])%mod)