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

n = set(list('yukicoder'))
dic = {i:idx for idx,i in enumerate('yukicoder')}
dp = [[[0]*2 for _ in range(9)] for _ in range(N)]
if S[0]=='y':
    dp[0][0][0] = 1
if S[0]=='?':
    dp[0][0][1] = 1

mod = 10**9+7
for i in range(1,N):
    for j in range(9):
        for k in range(2):
            dp[i][j][k] += dp[i-1][j][k]
            dp[i][j][k] %= mod
    if S[i] in n:
        idx = dic[S[i]]
        if idx==0:
            dp[i][idx][0] += 1
            dp[i][idx][0] %= mod
        else:
            dp[i][idx][0] += dp[i-1][idx-1][0]
            dp[i][idx][1] += dp[i-1][idx-1][1]
            dp[i][idx][0] %= mod
            dp[i][idx][1] %= mod
    elif S[i]=='?':
        for j in range(9):
            if j==0:
                dp[i][j][1] += 1
                dp[i][j][1] %= mod
            else:
                dp[i][j][1] += dp[i-1][j-1][0]
                dp[i][j][1] %= mod
print((dp[-1][-1][0]+dp[-1][-1][1])%mod)