#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int mod = 1e9 + 7;
int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	int n, m;
	cin >> n >> m;
	string s;
	cin >> s;
	vector<int>edge_p[n];
	vector<int>edge_d[n];
	vector<int>edge_c[n];
	for (int i = 0; i < m; i++) {
		int u, v;
		cin >> u >> v;
		--u, --v;
		if (s[u] > s[v])swap(u, v);
		if (s[v] == 'P' && s[u] == 'D') {
			edge_p[u].push_back(v);
			edge_p[v].push_back(u);
		}
		else if (s[u] == 'C' && s[v] == 'D') {
			edge_d[u].push_back(v);
			edge_d[v].push_back(u);
		}
		else if (s[u] == 'A' && s[v] == 'C') {
			edge_c[u].push_back(v);
			edge_c[v].push_back(u);
		}
	}
	vector<int>dp(n, 0);
	for (int i = 0; i < n; i++) {
		if (s[i] == 'P')dp[i] = 1;
	}
	for (int i = 0; i < n; i++) {
		if (s[i] == 'P') {
			for (auto k : edge_p[i]) {
				dp[k] += dp[i];
				dp[k] %= mod;
			}
		}
	}
	for (int i = 0; i < n; i++) {
		if (s[i] == 'D') {
			for (auto k : edge_d[i]) {
				dp[k] += dp[i];
				dp[k] %= mod;
			}
		}
	}
	for (int i = 0; i < n; i++) {
		if (s[i] == 'C') {
			for (auto k : edge_c[i]) {
				dp[k] = dp[i];
				dp[k] %= mod;
			}
		}
	}
	int ans = 0;
	for (int i = 0; i < n; i++) {
		if (s[i] == 'A') {
			ans += dp[i];
			ans %= mod;
		}
	}
	cout << ans << endl;
}