N = int(input())
S = input()
mod = 10**9+7
# i文字目まで見てyukicoderのj文字目まできて?をk個
yuki = 'yukicoder'
dp = [[0]*(len(yuki)+1) for i in range(2)]
dp[0][0] = 1
for i in range(N):
    if S[i] != "?":
        for j in range(1,len(yuki)+1):
            if S[i] == yuki[j-1]:
                dp[0][j] += dp[0][j-1]
                dp[0][j] %= mod
                dp[1][j] += dp[1][j-1]
                dp[1][j] %= mod
            
    if S[i] == "?":
        for j in range(1,len(yuki)+1):
            dp[1][j] += dp[0][j-1]
            dp[1][j] %= mod
print(dp[0][-1]+dp[1][-1])