#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0; i<(n); i++)
#define INF ((1LL<<62)-(1LL<<31))
#define all(a)  (a).begin(),(a).end()
#define rall(a)  (a).rbegin(),(a).rend()
typedef long long ll;
typedef pair<ll,ll> pl;

const ll mod=1000000007;
const string str="yukicoder";

ll dp[100010][10][2];

int main() {
    int n; string s;
    cin >> n >> s;
    dp[0][0][0]=1;
    rep(i,n) rep(j,10) rep(k,2) {
        dp[i+1][j][k]+=dp[i][j][k];
        dp[i+1][j][k]%=mod;
        if(j==9) continue;
        if(k==0) {
            if(str[j]==s[i]) dp[i+1][j+1][k]=(dp[i+1][j+1][k]+dp[i][j][k])%mod;
            else if(s[i]=='?') dp[i+1][j+1][1]=(dp[i+1][j+1][1]+dp[i][j][0])%mod;
        } else {
            if(str[j]==s[i]) dp[i+1][j+1][k]=(dp[i+1][j+1][k]+dp[i][j][k])%mod;
        }
    }
    cout << (dp[n][9][0]+dp[n][9][1])%mod << endl;
    return 0;
}