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

public class Main {
    static final int MOD = 1000000007;
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner();
        int n = sc.nextInt();
        int m = sc.nextInt();
        char[] types = sc.next().toCharArray();
        ArrayList<ArrayList<Integer>> graph = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            graph.add(new ArrayList<>());
        }
        for (int i = 0; i < m; i++) {
            int left = sc.nextInt() - 1;
            int right = sc.nextInt() - 1;
            if ((types[left] == 'P' && types[right] == 'D') ||
                (types[left] == 'D' && types[right] == 'C') ||
                (types[left] == 'C' && types[right] == 'A') ) {
                    graph.get(left).add(right);
            }
            if ((types[left] == 'D' && types[right] == 'P') ||
                (types[left] == 'C' && types[right] == 'D') ||
                (types[left] == 'A' && types[right] == 'C') ) {
                    graph.get(right).add(left);
            }
        }
        int[] counts = new int[n];
        for (int i = 0; i < n; i++) {
            if (types[i] == 'A') {
                counts[i] = 1;
            }
        }
        for (int i = 0; i < n; i++) {
            if (types[i] == 'C') {
                for (int x : graph.get(i)) {
                    counts[i] += counts[x];
                    counts[i] %= MOD;
                }
            }
        }
        for (int i = 0; i < n; i++) {
            if (types[i] == 'D') {
                for (int x : graph.get(i)) {
                    counts[i] += counts[x];
                    counts[i] %= MOD;
                }
            }
        }
        int ans = 0;
        for (int i = 0; i < n; i++) {
            if (types[i] == 'P') {
                for (int x : graph.get(i)) {
                    counts[i] += counts[x];
                    counts[i] %= MOD;
                }
                ans += counts[i];
                ans %= MOD;
            }
        }
        System.out.println(ans);
    }
}

class Scanner {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer st = new StringTokenizer("");
    
    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 String next() throws Exception {
        while (!st.hasMoreTokens()) {
            st = new StringTokenizer(br.readLine());
        }
        return st.nextToken();
    }
}