MOD = 10**9 + 7

n = int(input())
s = input().strip()

base = 'yukicoder'
targets = [base]
for i in range(len(base)):
    temp = list(base)
    temp[i] = '?'
    targets.append(''.join(temp))

result = 0

for target in targets:
    dp = [0] * (len(base) + 1)
    dp[0] = 1  # Initial state: 1 way to form an empty subsequence
    
    for c in s:
        # Iterate backwards to avoid overwriting the dp values we need to use
        for j in reversed(range(len(base))):
            if c == target[j]:
                dp[j+1] = (dp[j+1] + dp[j]) % MOD
    
    result = (result + dp[len(base)]) % MOD

print(result)