#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define REP(i, n) for (int i = 0; i < (n); ++i)
#define REPR(i, n) for (int i = n - 1; i >= 0; --i)
#define FOR(i, m, n) for (int i = m; i < n; ++i)
#define FORR(i, m, n) for (int i = m; i >= n; --i)
#define ALL(v) (v).begin(),(v).end()
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
const ll INF=1LL<<60;
const int inf=(1<<30)-1;
const int mod=1e9+7;
int dx[8]={1,0,-1,0,-1,-1,1,1};
int dy[8]={0,1,0,-1,-1,1,-1,1};
int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n;cin >> n;
    string s;cin >> s;
    string t="yukicoder";
    vector dp(n+1,vector(10,vector<ll>(2)));
    dp[0][0][0]=1;
    REP(i,n){
        REP(j,10){
            REP(k,2){
                if(j!=9){
                    (dp[i+1][j][k]+=dp[i][j][k])%=mod;
                    if(s[i]==t[j]) (dp[i+1][j+1][k]+=dp[i][j][k])%=mod;
                    else if(s[i]=='?'&&k==0) (dp[i+1][j+1][1]+=dp[i][j][0])%=mod;
                }
                else (dp[i+1][j][k]+=dp[i][j][k])%=mod;
            }
        }
    }
    cout << (dp[n][9][0]+dp[n][9][1])%mod << endl;
}