#include <bits/stdc++.h>
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using namespace atcoder;
#endif
#define rep(i, n) for (int i = 0; i < (n); ++i)

using std::cin;
using std::cout;
using std::string;
using mint = modint1000000007;

mint dp[100005][10][2];

int main() {
	int n;
	string s;
	cin >> n >> s;
	string t = "yukicoder";
	
	dp[0][0][0] = 1;
	rep(i, n)rep(j, 9)rep(k, 2) {
		dp[i + 1][j][k] += dp[i][j][k];
		if (s[i] == t[j]) {
			dp[i + 1][j + 1][k] += dp[i][j][k];
		}  
		if (s[i] == '?' and k == 0) {
			dp[i + 1][j + 1][k + 1] += dp[i][j][k];
		}
	}
	
	mint ans = dp[n][9][0] + dp[n][9][1];
	cout << ans.val() << '\n';
	
	return 0;
}