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

ll a[200005];
ll b[200005];

int main(){
  int n; cin >> n;
  string s; cin >> s;
  for(int i = 0; i < n; i++){
    ll num; cin >> num;
    if(s[i] == 'R') a[i] = num;
    else a[i] = -num;
  }
  b[0] = 0;
  for(int i = 0; i < n; i++) b[i+1] = b[i] + a[i];
  ll M = -1e18;
  ll m = 1e18;
  for(int i = 0; i <= n; i++){
    M = max(M, b[i]);
    m = min(m, b[i]);
  }
  ll ans = M - m;
  cout << ans << endl;
  return 0;
}