#include <bits/stdc++.h>

#include <atcoder/modint>
using namespace std;
using mint = atcoder::modint1000000007;
void fast_io() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
}

int main() {
    fast_io();
    int n;
    string s;
    cin >> n >> s;
    vector dp(10, vector<mint>(2));
    string y = "yukicoder";
    dp[0][0] = 1;
    for (int i = 0; i < n; i++) {
        if (s[i] == '?') {
            for (int j = 8; j >= 0; j--) {
                dp[j + 1][1] += dp[j][0];
            }
            continue;
        }
        int match = -1;
        for (int j = 0; j < 9; j++) {
            if (s[i] == y[j]) {
                match = j;
                break;
            }
        }
        if (match == -1) {
            continue;
        }
        dp[match + 1][0] += dp[match][0];
        dp[match + 1][1] += dp[match][1];
    }
    mint ans = dp[9][0] + dp[9][1];
    cout << ans.val() << endl;
}