using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var n = NN;
        var s = ReadLine();
        var dp = new long[n + 1][];
        dp[0] = new long[18];
        var y = "yukicoder";
        var mod = 1_000_000_007;
        for (var i = 1; i < dp.Length; ++i)
        {
            dp[i] = (long[]) dp[i - 1].Clone();
            if (s[i - 1] == y[0])
            {
                dp[i][0] = (dp[i][0] + 1) % mod;
            }
            else if (s[i - 1] == '?')
            {
                dp[i][9] = (dp[i][9] + 1) % mod;
                for (var j = 1; j < y.Length; ++j)
                {
                    dp[i][j + 9] = (dp[i][j + 9] + dp[i - 1][j - 1]) % mod;
                }
            }
            else for (var j = 1; j < y.Length; ++j) if (s[i - 1] == y[j])
            {
                dp[i][j] = (dp[i][j] + dp[i - 1][j - 1]) % mod;
                dp[i][j + 9] = (dp[i][j + 9] + dp[i - 1][j + 8]) % mod;
            }
        }
        WriteLine((dp[n][8] + dp[n][17]) % mod);
    }
}