import java.util.*;

public class Main {
    static final int MOD = 1000000007;
	public static void main (String[] args) {
    	Scanner sc = new Scanner(System.in);
    	int n = sc.nextInt();
    	int m = sc.nextInt();
    	char[] arr = 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 a = sc.nextInt() - 1;
    	    int b = sc.nextInt() - 1;
    	    graph.get(a).add(b);
    	    graph.get(b).add(a);
    	}
    	int[] pCounts = new int[n];
    	for (int i = 0; i < n; i++) {
    	    if (arr[i] == 'P') {
    	        pCounts[i]++;
    	    }
    	}
    	int[] dCounts = new int[n];
    	for (int i = 0; i < n; i++) {
    	    if (arr[i] != 'D') {
    	        continue;
    	    }
    	    for (int x : graph.get(i)) {
    	        dCounts[i] += pCounts[x];
    	        dCounts[i] %= MOD;
    	    }
    	}
    	int[] cCounts = new int[n];
    	for (int i = 0; i < n; i++) {
    	    if (arr[i] != 'C') {
    	        continue;
    	    }
    	    for (int x : graph.get(i)) {
    	        cCounts[i] += dCounts[x];
    	        cCounts[i] %= MOD;
    	    }
    	}
    	int total = 0;
    	for (int i = 0; i < n; i++) {
    	    if (arr[i] != 'A') {
    	        continue;
    	    }
    	    for (int x : graph.get(i)) {
    	        total += cCounts[x];
    	        total %= MOD;
    	    }
    	}
    	System.out.println(total);
    }
}