#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cmath>
#include<cctype>
#include<math.h>
#include<string>
#include<string.h>
#include<stack>
#include<queue>
#include<vector>
#include<utility>
#include<set>
#include<map>
#include<stdlib.h>
#include<iomanip>

using namespace std;

#define ll long long
#define ld long double
#define EPS 0.0000000001
#define INF 1e9
#define LINF (ll)INF*INF
#define MOD 1000000007
#define rep(i,n) for(int i=0;i<(n);i++)
#define loop(i,a,n) for(int i=a;i<(n);i++)
#define all(in) in.begin(),in.end()
#define shosu(x) fixed<<setprecision(x)

#define int ll //!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

typedef vector<int> vi;
typedef vector<string> vs;
typedef pair<int,int> pii;
typedef vector<pii> vp;

int gcd(int a, int b){
    if(b==0) return a;
    return gcd(b,a%b);
}
int lcm(int a, int b){
    return a/gcd(a,b)*b;
}


signed main(void) {
    int n,m;
    cin >> n >> m;
    string s;
    cin >> s;
    vector<vi> g(n);
    rep(i,m){
        int a,b;
        cin >> a >> b;
        a--,b--;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    vi dp(n,0);
    rep(i,n)if(s[i] == 'P')dp[i]++;
    rep(i,n)if(s[i] == 'D'){
        rep(j,g[i].size()){
            int ind = g[i][j];
            if(s[ind] != 'P')continue;
            (dp[i] += dp[ind]) %= MOD;
        }
    }
    rep(i,n)if(s[i] == 'C'){
        rep(j,g[i].size()){
            int ind = g[i][j];
            if(s[ind] != 'D')continue;
            (dp[i] += dp[ind]) %= MOD;
        }
    }
    int ans = 0;
    rep(i,n)if(s[i] == 'A'){
        rep(j,g[i].size()){
            int ind = g[i][j];
            if(s[ind] != 'C')continue;
            (ans += dp[ind]) %= MOD;
        }
    }
    cout << ans << endl;
}