#include <iostream>
#include <vector>

using namespace std;
using ll=long long;

int main(){
    ll n;
    cin>>n;
    string s;
    cin>>s;
    ll rsum=0,bsum=0;
    ll mi=0,ma=0;
    for(ll i=0;i<n;i++){
        ll a;
        cin>>a;
        if(s[i]=='R'){
            rsum+=a;
        }else{
            bsum-=a;
        }
        mi=min(mi,rsum+bsum);
        ma=max(ma,rsum+bsum);
    }

    cout<<abs(ma-mi)<<endl;
    return 0;
}