#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1000000007;
vector<int> z_algorithm(vector<pair<char, int>> S){
  int N = S.size();
  vector<int> ans(N);
  for (int i = 1, j = 0; i < N; i++){
    if (i + ans[i - j] < j + ans[j]){
      ans[i] = ans[i - j];
    } else {
      int k = max(0, j + ans[j] - i);
      while (i + k < N && S[k] == S[i + k]){
        k++;
      }
      ans[i] = k;
      j = i;
    }
  }
  ans[0] = N;
  return ans;
}
long long tri(long long n){
  return n * (n + 1) / 2 % MOD;
}
int main(){
  int N;
  cin >> N;
  vector<int> A(N);
  for (int i = 0; i < N; i++){
    cin >> A[i];
  }
  string S;
  cin >> S;
  if (N == 1){
    cout << tri(A[0]) << endl;
  } else {
    vector<long long> sum(N + 1);
    sum[0] = 0;
    for (int i = 0; i < N; i++){
      sum[i + 1] = sum[i] + A[i];
    }
    vector<pair<char, int>> T(N - 1);
    for (int i = 0; i < N - 1; i++){
      T[i] = make_pair(A[i + 1], S[i + 1]);
    }
    vector<int> Z = z_algorithm(T);
    long long ans = sum[N] + tri(A[0] - 1);
    for (int i = 1; i < N; i++){
      if (S[i] == S[0]){
        if (A[i] < A[0]){
          ans += tri(A[i]);
        } else {
          ans += tri(A[0] - 1);
          ans += (long long) A[0] * (A[i] - A[0]) % MOD;
          if (i < N - 1){
            ans += sum[Z[i] + 1];
            int x = Z[i] + 1;
            int y = Z[i] + i + 1;
            if (y < N){
              if (S[x] == S[y]){
                ans += min(A[x], A[y]);
              }
            }
          } else {
            ans += A[0];
          }
        }
      }
      ans %= MOD;
    }
    cout << ans << endl;
  }
}