#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 a[26];
    for(int i=0;i<26;i++)
        cin>>a[i];
    string str;
    cin>>str;
    int max=-1;
    for(int i=0;i<str.length();i++)
        {
        if(a[str[i]%97]>max)
            max=a[str[i]%97];
    }
    cout<<max*str.length();
    return 0;
}