#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */ 
    int i,j,k,m,a[26];string s;
    for(i=0;i<26;i++)
        {
        cin>>a[i];
    }
    cin>>s;int ma=-1;
    for(i=0;i<s.length();i++)
        {
        ma=max(ma,a[s[i]-'a']);
    }
    cout<<ma*s.length();
    return 0;
}