N = int(input())
S = input().strip()
T = "yukicoder"
K = len(T)
MOD = 10**9+7
dp = [[0 for _ in range(K)] for _ in range(N)]
if S[0]==T[0]:
    dp[0][0] = 1
for i in range(1,N):
    dp[i][0] = dp[i-1][0]
    if S[i]==T[0]:
        dp[i][0] += 1
for i in range(1,N):
    for j in range(1,K):
        dp[i][j] = dp[i-1][j]
        if S[i]==T[j]:
            dp[i][j] = (dp[i][j]+dp[i-1][j-1])%MOD
ans = dp[N-1][K-1]
for k in range(K):
    T1 = T[:k]+"?"+T[k+1:]
    dp = [[0 for _ in range(K)] for _ in range(N)]
    if S[0]==T1[0]:
        dp[0][0] = 1
    for i in range(1,N):
        dp[i][0] = dp[i-1][0]
        if S[i]==T1[0]:
            dp[i][0] += 1
    for i in range(1,N):
        for j in range(1,K):
            dp[i][j] = dp[i-1][j]
            if S[i]==T1[j]:
                dp[i][j] = (dp[i][j]+dp[i-1][j-1])%MOD
    ans = (ans+dp[N-1][K-1])%MOD
print(ans)