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

#define int long long

#define pb push_back
#define fi first
#define se second
#define rep(i,s,n) for(int i = s;i<n;i++)
#define repe(i,s,n) for(int i = s;i<=n;i++)
#define rrep(i,s,n) for(int i = (n)-1;i>=(s);i--)
#define all(v) (v).begin(),(v).end()
#define chmin(a,b) a=min((a),(b))
#define chmax(a,b) a=max((a),(b))
#define low(a,b) lower_bound(all(a),(b))
#define upp(a,b) upper_bound(all(a),(b))
#define fill(i,n) memset(i,n,sizeof(i))
#define endl '\n'
#define IOS() ios_base::sync_with_stdio(0);cin.tie(0)
typedef long long ll;
typedef pair<int,int>pint;
typedef vector<int>vint;
typedef vector<vint> vvint;
typedef vector<pint>vpint;
typedef pair<pint,int> P1;
typedef pair<int,pint> P2;
typedef pair<pint,pint> PP;
static const ll maxLL = (ll)1 << 62;
const ll MOD=1000000007;
const ll INF=1e18;

int N,M,a,b;
string s;
int dp[100010];
vint cnt[4],tree[100010];
map<char,int>mmap;

signed main() {
    IOS();
    //(1ll<<N)シフト演算のオーバーフローに気をつける
    cin>>N>>M>>s;
    mmap['P']=0;mmap['D']=1;mmap['C']=2;mmap['A']=3;
    rep(i,0,N){
        if(s[i]=='P'){
            cnt[0].pb(i);
            dp[i]=1;
        }else if(s[i]=='D')cnt[1].pb(i);
        else if(s[i]=='C')cnt[2].pb(i);
        else cnt[3].pb(i);
    }
    
    rep(i,0,M){
        cin>>a>>b;a--;b--;
        if(mmap[s[b]]==mmap[s[a]]+1)tree[a].pb(b);
        if(mmap[s[a]]==mmap[s[b]]+1)tree[b].pb(a);
    }
    rep(i,0,4)for(auto e:cnt[i])for(auto ee:tree[e])dp[ee]+=dp[e];
    
    int ans=0;
    rep(i,0,N)if(s[i]=='A'){
        ans+=dp[i];
        ans%=MOD;
    }
    cout<<ans<<endl;
    
    
    
    
    
    

    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    




















































    return 0;
}