#include <stdio.h>
#include <vector>
using namespace std;

vector<int> G[100100];
int N,M,D[4][100100]; char S[100100];

int main()
{
	scanf ("%d %d %s",&N,&M,S+1);
	for (int i=0;i<M;i++){
		int x,y; scanf ("%d %d",&x,&y);
		G[x].push_back(y);
		G[y].push_back(x);
	}

	const int mod = 1000000007;
	for (int i=1;i<=N;i++) if (S[i] == 'P') D[0][i] = 1;
	for (int i=1;i<=N;i++) if (S[i] == 'D') for (int j : G[i]) D[1][i] = (D[1][i] + D[0][j]) % mod;
	for (int i=1;i<=N;i++) if (S[i] == 'C') for (int j : G[i]) D[2][i] = (D[2][i] + D[1][j]) % mod;
	for (int i=1;i<=N;i++) if (S[i] == 'A') for (int j : G[i]) D[3][i] = (D[3][i] + D[2][j]) % mod;
	int ans = 0;
	for (int i=1;i<=N;i++) ans = (ans + D[3][i]) % mod;
	printf ("%d\n",ans);

	return 0;
}