#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000001

long long get(vector<long long> A){
	long long mini = 0LL;
	long long cur = 0LL;
	long long ret = 0LL;
	rep(i,A.size()){
		cur += A[i];
		ret = max(ret,cur - mini);
		mini = min(mini,cur);
	}
	return ret;
}

int main(){
	int N;
	cin>>N;
	
	string S;
	cin>>S;
	
	vector<long long> A(N);
	rep(i,N){
		scanf("%lld",&A[i]);
		if(S[i]=='B')A[i] *= -1;
	}
	
	long long ans = get(A);
	rep(i,N)A[i] *= -1;
	ans = max(ans,get(A));
	
	cout<<ans<<endl;
	
    return 0;
}