// yukicoder: No.762 PDCAパス
// 2019.7.10 bal4u

#include <stdio.h>
#include <string.h>

#if 1
#define gc() getchar_unlocked()
#else
#define gc() getchar()
#endif

int in() {   // 非負整数の入力
	int n = 0, c = gc();
	do n = 10 * n + (c & 0xf); while ((c = gc()) >= '0');
	return n;
}

// 文字列の入力　スペース以下の文字で入力終了
void ins(char *s) {
	do *s = gc(); while (*s++ > ' ');
	*(s - 1) = 0;
}

#define MOD 1000000007
#define MAX 100005
typedef struct { int u, v; } T;
T to[4][MAX]; int hi[4];
char S[MAX];
signed char idx['P' + 1]['P' + 1];
int node[MAX];

int main()
{
	int i, j, u, v, N, M;
	long long ans;

	idx['P']['D'] = 1, idx['D']['P'] = -1;
	idx['D']['C'] = 2, idx['C']['D'] = -2;
	idx['C']['A'] = 3, idx['A']['C'] = -3;
	N = in(), M = in();
	ins(S);
	while (M--) {
		u = in() - 1, v = in() - 1;
		i = idx[S[u]][S[v]];
		if (i > 0) to[i][hi[i]].u = u, to[i][hi[i]++].v = v;
		else if (i < 0) i = -i, to[i][hi[i]].u = v, to[i][hi[i]++].v = u;
	}
	
	for (i = 0; i < hi[1]; i++) node[to[1][i].u] = 1;
	for (j = 1; j <= 3; j++) for (i = 0; i < hi[j]; i++)
		node[to[j][i].v] += node[to[j][i].u];

	ans = 0;
	for (i = 0; i < hi[3]; i++) {
		ans += node[to[3][i].v];
		node[to[3][i].v] = 0;
	}
	printf("%d\n", (int)(ans % MOD));
	return 0;
}