#include <bits/stdc++.h>
using namespace std;

int main() {
    int N, M;
    cin >> N >> M;
    string S;
    cin >> S;
    vector<vector<int>> adj(N);
    for (int i = 0; i < M; i++) {
        int u, v;
        cin >> u >> v;
        u--;
        v--;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    long long DP[N] = {};
    for (int i = 0; i < N; i++) {
        if (S[i] == 'P') {
            DP[i] = 1;
        }
    }
    for (int i = 0; i < N; i++) {
        if (S[i] == 'D') {
            for (const auto& x : adj[i]) {
                if (S[x] == 'P') {
                    DP[i] += DP[x];
                }
            }
        }
    }
    for (int i = 0; i < N; i++) {
        if (S[i] == 'C') {
            for (const auto& x : adj[i]) {
                if (S[x] == 'D') {
                    DP[i] += DP[x];
                }
            }
        }
    }
    long long ans = 0;
    for (int i = 0; i < N; i++) {
        if (S[i] == 'A') {
            for (const auto& x : adj[i]) {
                if (S[x] == 'C') {
                    ans += DP[x];
                }
            }
        }
    }
    cout << ans % 1000000007 << endl;
}