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);
        }
        int length = yukicoder.length;
        int[] dp1 = new int[length + 1];
        int[] dp2 = new int[length + 1];
        dp1[0] = 1;
        dp2[0] = 1;
        for (char c : inputs) {
            if (c == '?') {
                for (int i = length; i > 0; i--) {
                    dp1[i] += dp2[i - 1];
                    dp1[i] %= MOD;
                }
            } else {
                if (idxes.containsKey(c)) {
                    int x = idxes.get(c) + 1;
                    dp1[x] += dp1[x - 1];
                    dp1[x] %= MOD;
                    dp2[x] += dp2[x - 1];
                    dp2[x] %= MOD;
                }
            }
        }
        System.out.println(dp1[length]);
    }
}
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();
    }
    
}