#!/bin/python

import sys


h = map(int,raw_input().strip().split(' '))
word = raw_input().strip()

def cal (h):
    for i in h:
        if (i <1)&(i>7):
            return False
    return True 

if (len (word)<=10):
    if (cal (h)):
        h1=h [ord(word[0])-97:ord (word[len (word)-1])-96]
        print max(h1)*len(h1)