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[] tam = new int[26]; for (int i = 0; i < 26; i++) { tam[i] = in.nextInt(); } String s = in.next(); designerPDFViewer(tam, s); } private static void designerPDFViewer(int[] tam, String s) { char[] c = s.toCharArray(); int max = 0; for (int i = 0; i < c.length; i++) { max = Math.max(max, tam[c[i] - 'a']); } System.out.println(max * s.length()); } }