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

#undef _P
#define _P(...) (void)printf(__VA_ARGS__)
#define FOR(x,to) for(x=0;x<(to);x++)
#define FORR(x,arr) for(auto& x:arr)
#define ITR(x,c) for(__typeof(c.begin()) x=c.begin();x!=c.end();x++)
#define ALL(a) (a.begin()),(a.end())
#define ZERO(a) memset(a,0,sizeof(a))
#define MINUS(a) memset(a,0xff,sizeof(a))
//-------------------------------------------------------


int N,M;
string S;
vector<int> E[101010];

vector<int> C[4];
int st[101010];
ll dp[101010];
ll mo=1000000007;


void solve() {
	int i,j,k,l,r,x,y; string s;
	
	cin>>N>>M>>S;
	FOR(i,N) {
		if(S[i]=='P') st[i]=0;
		if(S[i]=='D') st[i]=1;
		if(S[i]=='C') st[i]=2;
		if(S[i]=='A') st[i]=3;
		if(st[i]==0) dp[i]=1;
	}
	FOR(i,M) {
		cin>>x>>y;
		E[x-1].push_back(y-1);
		E[y-1].push_back(x-1);
	}
	
	FOR(i,3) {
		FOR(j,N) if(st[j]==i) {
			FORR(e,E[j]) if(st[e]==st[j]+1) {
				(dp[e]+=dp[j])%=mo;
			}
		}
	}
	ll ret=0;	
	FOR(i,N) if(st[i]==3) ret+=dp[i];
	cout<<ret%mo<<endl;
	
}


int main(int argc,char** argv){
	string s;int i;
	if(argc==1) ios::sync_with_stdio(false), cin.tie(0);
	FOR(i,argc-1) s+=argv[i+1],s+='\n'; FOR(i,s.size()) ungetc(s[s.size()-1-i],stdin);
	cout.tie(0); solve(); return 0;
}