import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		char[] s = sc.next().toCharArray();
		sc.close();

		char[] t = "yukicoder".toCharArray();
		int m = t.length;
		int m1 = m + 1;
		int m2 = m1 * 2;
		int mod = 1000000007;
		long[][] dp = new long[n + 1][m2];
		dp[0][0] = 1;
		for (int i = 0; i < n; i++) {
			if (s[i] == '?') {
				for (int j = 0; j < m; j++) {
					dp[i + 1][m1 + j + 1] += dp[i][j];
				}
			} else {
				for (int j = 0; j < m; j++) {
					if (s[i] == t[j]) {
						dp[i + 1][j + 1] += dp[i][j];
						dp[i + 1][m1 + j + 1] += dp[i][m1 + j];
					}
				}
			}
			for (int j = 0; j < m2; j++) {
				dp[i + 1][j] += dp[i][j];
				dp[i + 1][j] %= mod;
			}
		}
		long ans = dp[n][m1 - 1] + dp[n][m2 - 1];
		ans %= mod;
		System.out.println(ans);
	}
}