#include<stdlib.h>
#include<vector>
#include<stdio.h>
#include<math.h>
#include<algorithm>
#include<string.h>
#include <iostream>
#include<bits/stdc++.h>
using namespace std;
unsigned long long int mod=1000000007;
typedef long long int ll;
int main() 
{
    ll a[27];
    ll i,j,k,count=0;
    for(i=0;i<26;i++)
        cin>>a[i];
    string s;
    cin>>s;
    ll max=0;
    for(i=0;i<s.length();i++)
        {
        //cout<<s[i]-'a'<<endl;
        if(max<a[s[i]-'a'])
            max=a[s[i]-'a'];
    }
    cout<<max*s.length()<<endl;
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    return 0;
}