#include <bits/stdc++.h>
using namespace std;
using std::cout;
using std::cin;
using std::endl;
using ll=long long;
ll mod=1e9+7;
#define rep(i,a) for (int i=0;i<a;i++)

const int MAX_N=2e5;
const int MAX_A=1e9;
const int TYPE=26;

//おちこんだりもしたけれど、私はげんきです。
int main() {
	int N;
	cin>>N;
	vector<ll> A(N);
	string S;
	rep(i,N) cin>>A[i];
	cin>>S;
	assert(1<=N&&N<=MAX_N);
	assert((int)(S.size())==N);
	rep(i,N){
		assert(1<=A[i]&&A[i]<=MAX_A);
		assert('a'<=S[i]&&S[i]<='z');
		if(i!=0){
			assert(S[i]!=S[i-1]);
		}
	}
	ll ans=0;
	vector<queue<int>> cha_ind(TYPE);
	vector<ll> dp(N+1);
	rep(i,N) cha_ind[(int)(S[i]-'a')].push(i);
	rep(i,TYPE){
		cha_ind[i].push(N);
		dp[cha_ind[i].front()]++;
	}

	rep(i,N){
		dp[i]%=mod;
		ans=(ans+(dp[i]*A[i])%mod)%mod;
		rep(k,TYPE){
			if(cha_ind[k].front()==i){
				cha_ind[k].pop();
				dp[cha_ind[k].front()]+=dp[i];
			}
			else dp[cha_ind[k].front()]+=(dp[i]*A[i])%mod;
		}
	}
	cout<<ans<<endl;
}