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

typedef long long ll;
#define int ll
#define _FastIO ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define pb emplace_back
#define pii pair<int , int>
#define F first
#define S second
const int mod = 1000000007;
const int MAXX = 2e5 + 5;

int n , k;
string s;
int a[MAXX];

signed main()
{
    _FastIO;
    cin >> n;
    int x = 0 , y = 0;
    int p = 0;
    cin >> s;
    int ans = 0;
    for(int i = 0; i < n; i++){
        cin >> a[i];
        if(s[i] == 'B')
            x += a[i];
        else
            y += a[i];
        p = min(p , x - y);
        ans = max(ans , x - y - p);
    }
    x = 0;
    y = 0;
    p = 0;
    for(int i = 0; i < n; i++){
        if(s[i] == 'B')
            x += a[i];
        else
            y += a[i];
        p = min(p , y - x);
        ans = max(ans , y - x - p);
    }
    cout << ans << endl;
    return 0;
}