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

#define FOR(i,a,b) for(ll i=(a);i<(b);++i)
#define ALL(v) (v).begin(), (v).end()
#define p(s) cout<<(s)<<endl
#define p2(s, t) cout << (s) << " " << (t) << endl
#define br() p("")
#define pn(s) cout << (#s) << " " << (s) << endl
#define p_yes() p("Yes")
#define p_no() p("No")

const ll mod = 1e9 + 7;
const ll inf = 1e18;

const int N_MAX = 100010;
ll dp[N_MAX];

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    // input
    ll N, M;
    cin >> N >> M;

    string s;
    cin >> s;

    vector<ll> U(M);
    vector<ll> V(M);
    FOR(i, 0, M){
        ll u, v;
        cin >> u >> v;
        u--;
        v--;
        U[i] = u;
        V[i] = v;
    }

    // P->D
    FOR(i, 0, M){
        ll u = U[i];
        ll v = V[i];

        if(s[u]=='P' && s[v]=='D'){
            dp[v]++;
        }
        swap(u, v);
        if(s[u]=='P' && s[v]=='D'){
            dp[v]++;
        }
    }
    
    // D->C
    FOR(i, 0, M){
        ll u = U[i];
        ll v = V[i];

        if(s[u]=='D' && s[v]=='C'){
            dp[v] += dp[u];
            dp[v] %= mod;
        }
        swap(u, v);
        if(s[u]=='D' && s[v]=='C'){
            dp[v] += dp[u];
            dp[v] %= mod;
        }
    }

    // C->A
    FOR(i, 0, M){
        ll u = U[i];
        ll v = V[i];

        if(s[u]=='C' && s[v]=='A'){
            dp[v] += dp[u];
            dp[v] %= mod;
        }
        swap(u, v);
        if(s[u]=='C' && s[v]=='A'){
            dp[v] += dp[u];
            dp[v] %= mod;
        }
    }

    ll sum = 0;
    FOR(i, 0, N){
        if(s[i]=='A'){
            sum += dp[i];
            sum %= mod;
        }
    }

    p(sum);
    
    return 0;
}