#include <bits/stdc++.h>
#include <atcoder/modint>
using namespace std;
using mint = atcoder::static_modint<(int)1e9+7>;
mint dp[1<<17][10];
int n;
string s;
mint solve(const string& tar) {
	memset(dp,0,sizeof(dp));
	dp[0][0] = 1;
	for(int i = 0; i < n; i++) {
		for(int j = 0; j < tar.size(); j++) {
			dp[i + 1][j] += dp[i][j];
			if(tar[j] == s[i]) dp[i + 1][j + 1] += dp[i][j];
		}
	}
	return dp[n][tar.size()];
}
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";
}