#include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <queue>
#include <algorithm>
#include <numeric>
#include <deque>
#include <complex>
#include <cassert>

using namespace std;

const long long modc=1e9+7;

int main(){

    long long N;
    cin >> N;
    string S, T="yukicoder";
    cin >> S;
    vector<vector<vector<long long>>> dp(N+1, vector(10, vector<long long>(2)));
    for (int i=0; i<=N; i++) dp[i][0][0] = 1;
    for (int i=1; i<=N; i++){
        for (int j=1; j<=9; j++){
            dp[i][j][0] += dp[i-1][j][0]; dp[i][j][0] %= modc;
            if (S[i-1] == T[j-1]){
                dp[i][j][0] += dp[i-1][j-1][0]; dp[i][j][0] %= modc;
            }

            dp[i][j][1] += dp[i-1][j][1]; dp[i][j][1] %= modc;
            if (S[i-1] == T[j-1]){
                dp[i][j][1] += dp[i-1][j-1][1]; dp[i][j][1] %= modc;
            }
            if (S[i-1] == '?'){
                dp[i][j][1] += dp[i-1][j-1][0]; dp[i][j][1] %= modc;
            }   
        }
    }

    cout << (dp[N][9][0] + dp[N][9][1]) % modc << endl;

    return 0;
}