import sys
readline=sys.stdin.readline

N=int(readline())
S=readline().rstrip()
lst=["yukicoder"]
for i in range(9):
    s="yukicoder"
    s=s[:i]+"?"+s[i+1:]
    lst.append(s)
mod=10**9+7
ans=0
for ss in lst:
    dp=[0]*10
    dp[0]=1
    for s in S:
        prev=dp
        dp=[x for x in dp]
        for i in range(9):
            if ss[i]==s:
                dp[i+1]+=prev[i]
                dp[i+1]%=mod
    ans+=dp[9]
    ans%=mod
print(ans)