mod = 10**9+7
N = int(input())
S = input()
T = 'yukicoder'
DP = [[0] * 10 for _ in range(N+1)]
DP[0][0] = 1
for i in range(N):
    for j in range(9):
        if S[i] == T[j]:
            DP[i+1][j+1] += DP[i][j]
    if S[i] == '?':
        for j in range(9):
            DP[i+1][j+1] += DP[i][j]
    for j in range(10):
        DP[i+1][j] += DP[i][j]
        DP[i+1][j] %= mod
print(DP[N][-1])