#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define ALL(v) v.begin(),v.end()
typedef long long ll;
 
#include<bits/stdc++.h>
using namespace std;

const ll INF=1e18+7;

int main(){
  int n;
  string s;
  cin>>n>>s;
  vector<ll> A(n+1);
  A[0]=0;
  rep(i,n){
    ll x;
    cin>>x;
    if(s[i]=='R') A[i+1]=x;
    else A[i+1]=-x;
  }
  
  ll ma=-INF,mi=INF,tmp=0;
  rep(i,n+1){
    tmp+=A[i];
    ma=max(ma,tmp);
    mi=min(mi,tmp);
  }
  cout<<abs(ma-mi)<<endl;
      
  return 0;
}