import static java.util.Arrays.setAll;

import java.io.FileNotFoundException;
import java.util.Scanner;

public class Task1 {
    
    public static void main(String[] args) throws FileNotFoundException {
        Scanner scanner = System.getProperty("local") == null? 
                new Scanner(System.in): new Scanner(Task1.class.getResourceAsStream("Task1.in"));
        while (scanner.hasNext()) {
            int[] H = new int[26];
            setAll(H, i -> scanner.nextInt());
            String s = scanner.next();
            int h = s.chars().map(c -> H[c - 'a']).max().getAsInt();
            System.out.println(h * s.length());
        }
        scanner.close();
    }

}