#include <bits/stdc++.h>
#include <atcoder/modint>
using namespace std;
using mint = atcoder::static_modint<(int)1e9+7>;
int n;
string s;
mint solve(const string& tar) {
	vector<vector<mint>> dp(tar.size()+1, vector<mint>(n+1, 0));
    for(int i = 0; i < n; i++) dp[0][i] = 1;
	for(int i = 0; i < tar.size(); i++) {
		for(int j = 0; j < n; j++) {
            if(tar[i]==s[j]) dp[i+1][j+1] = dp[i][j] + dp[i+1][j];
            else dp[i+1][j+1] = dp[i+1][j];
        }
    }
	return dp[tar.size()][n];
}
int main() {
	std::ios_base::sync_with_stdio(false);
	std::cin.tie(nullptr);
	cin >> n >> s;
	string t = "yukicoder";
	mint ans = solve(t);
	for(int i = 0; i < t.size(); i++) {
		char y = t[i];
		t[i] = '?';
		ans += solve(t);
		t[i] = y;
	}
	cout << ans.val() << "\n";
}