#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, srt, end) for (long long i = (srt); i < (long long)(end); i++)
// Ref: https://qiita.com/ysuzuki19/items/d89057d65284ba1a16ac
#define dump(var)  do{std::cerr << #var << " : ";view(var);}while(0)
template<typename T> void view(T e){std::cerr << e << "\n";}
template<typename T> void view(const std::vector<T>& v){for(const auto& e : v){ std::cerr << e << " "; } std::cerr << "\n";}
template<typename T> void view(const std::vector<std::vector<T> >& vv){ std::cerr << "\n"; for(const auto& v : vv){ view(v); } }
template<typename T> void dump_cout(const T& v) { for(long long i = 0; i < v.size(); i++) std::cout << v[i] << (i == v.size()-1 ? "\n" : " "); }

#include <atcoder/modint>
using mint = atcoder::modint1000000007;

#define N 100010
mint dp[N][10][2];

void solve() {
    ll n;
    string s;
    cin >> n >> s;
    dp[0][0][0] = 1;
    string t = "yukicoder";
    rep(i, 0, n) {
        rep(j, 0, 10) {
            rep(k, 0, 2) dp[i+1][j][k] += dp[i][j][k];
            if(s[i] == '?') dp[i+1][j+1][1] += dp[i][j][0];
        }
        rep(j, 0, 9) {
            if(s[i] == t[j]) {
                rep(k, 0, 2) dp[i+1][j+1][k] += dp[i][j][k];
            }
        }
    }
    mint ans = dp[n][t.size()][0] + dp[n][t.size()][1];
    cout << ans.val() << endl;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    solve();
    return 0;
}