#include<bits/stdc++.h>
// #include<atcoder/all>
// #include<boost/multiprecision/cpp_int.hpp>

using namespace std;
// using namespace atcoder;
// using bint = boost::multiprecision::cpp_int;
using ll = long long;
using ull = unsigned long long;
using P = pair<int,int>;
#define rep(i,n) for(ll i = 0;i < (ll)n;i++)
#define ALL(x) (x).begin(),(x).end()
#define MOD 1000000007


//連続する区間和の最大値
ll kadane(vector<ll> &v){
  ll res = -1e18;
  ll s = 0;
  rep(i,v.size()){
    s = max(s+v[i],v[i]);
    res = max(res,s);
  }
  return res;
}

int main(){
  
  int n;
  string s;
  cin >> n >> s;
  vector<ll> a(n);
  rep(i,n)cin >> a[i];
  rep(i,n)if(s[i] == 'B')a[i] *= (-1);
  ll res = kadane(a);
  rep(i,n)a[i] *= (-1);
  res = max(res,kadane(a));
  cout << res << "\n";


  return 0;
}