import std.stdio, std.array, std.string, std.conv, std.algorithm;
import std.typecons, std.range, std.random, std.math, std.container;
import std.numeric, std.bigint, core.bitop;

immutable long MOD = 10^^9 + 7;

void main() {
    auto N = readln.chomp.to!int;
    auto S = readln.chomp;
    auto yukicoder = "yukicoder";

    auto dp = new long[][][](N+1, 10, 2);
    dp[0][0][0] = 1;

    foreach (i; 0..N) foreach (j; 0..10) foreach (k; 0..2) {
        (dp[i+1][j][k] += dp[i][j][k]) %= MOD;
        if (j == 9) continue;
        if (k == 0 && S[i] == '?') {
            (dp[i+1][j+1][1] += dp[i][j][k]) %= MOD;
        }
        if (S[i] == yukicoder[j]) {
            (dp[i+1][j+1][k] += dp[i][j][k]) %= MOD;
        }
    }

    writeln(dp[N][9].sum % MOD);
}