import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n=in.nextInt();
        int h[] = new int[n];
        for(int h_i=0; h_i < n; h_i++){
            h[h_i] = in.nextInt();
        }
        String word = in.next();
         int l=word.length();
         int index=(int) word.charAt(0)-49;
        
        int hh=h[index];
        for(int i=0;i<l;i++){
            word.charAt(i);
            if(h[((int) word.charAt(i))-49]>hh){
                hh=h[((int) word.charAt(i)) -49];
            }
           
        }
       
        System.out.println(l*hh);
    }
}