import java.io.*;
import java.util.*;
import java.util.stream.*;

public class Main {
    static final int MOD = 1000000007;
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        char[] inputs = sc.next().toCharArray();
        char[] yukicoder = "yukicoder".toCharArray();
        HashMap<Character, Integer> idxes = new HashMap<>();
        for (int i = 0; i < yukicoder.length; i++) {
            idxes.put(yukicoder[i], i + 1);
        }
        int[][] counts = new int[yukicoder.length + 1][2];
        counts[0][0] = 1;
        for (char c : inputs) {
            if (idxes.containsKey(c)) {
                int i = idxes.get(c);
                counts[i][0] += counts[i - 1][0];
                counts[i][0] %= MOD;
                counts[i][1] += counts[i - 1][1];
                counts[i][1] %= MOD;
            } else if (c == '?') {
                for (int i = 1; i <= yukicoder.length; i++) {
                    counts[i][1] += counts[i - 1][0];
                    counts[i][1] %= MOD;
                }
            }
        }
        System.out.println((counts[yukicoder.length][0] + counts[yukicoder.length][1]) % MOD);
    }
}
class Utilities {
    static String arrayToLineString(Object[] arr) {
        return Arrays.stream(arr).map(x -> x.toString()).collect(Collectors.joining("\n"));
    }
    
    static String arrayToLineString(int[] arr) {
        return String.join("\n", Arrays.stream(arr).mapToObj(String::valueOf).toArray(String[]::new));
    }
}
class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    StringBuilder sb = new StringBuilder();
    
    public Scanner() throws Exception {
        
    }
    
    public int nextInt() throws Exception {
        return Integer.parseInt(next());
    }
    
    public long nextLong() throws Exception {
        return Long.parseLong(next());
    }
    
    public double nextDouble() throws Exception {
        return Double.parseDouble(next());
    }
    
    public int[] nextIntArray() throws Exception {
        return Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
    }
    
    public String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
    
}