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

int n;
string s;

int main() {
  long long res = 0, pls = 0, mns = 0, now = 0;
  cin >> n >> s;
  for (int i = 0; i < n; ++i) {
    long long p;
    cin >> p;
    if (s[i] == 'R')
      now += p;
    else
      now -= p;
    res = max({res, now - pls, mns - now});
    pls = min(pls, now);
    mns = max(mns, now);
  }
  cout << res << endl;
  return 0;
}