import sys,random
from collections import deque
from heapq import heappush,heappop

input = lambda :sys.stdin.readline().rstrip()
mi = lambda :map(int,input().split())
li = lambda :list(mi())

mod = 10**9 + 7

N = int(input())
S = input()

T = "yukicoder"

dp = [0 for i in range(2*len(T)+2)]
dp[0] = 1
for i in range(N):
    ndp = [x for x in dp]
    for j in range(len(T)):
        if S[i]==T[j]:
            ndp[2*j+2] += dp[2*j]
            ndp[2*j+2] %= mod

            ndp[2*j+3] += dp[2*j+1]
            ndp[2*j+3] %= mod
        
        elif S[i]=="?":
            ndp[2*j+3] += dp[2*j]
            ndp[2*j+3] %= mod
    
    dp = ndp

res = dp[2*len(T)] + dp[2*len(T)+1]
print(res % mod)