#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 */   
    string s;
    int a[123];
    int maxi=0;
    for(int i=97;i<123;i++)
        {
        cin>>a[i];   
    }
    cin>>s;
    int k=s.length();
    for(int i=0;i<k;i++)
        {
        maxi=max(maxi,a[s[i]]);
    }
    cout<<maxi*k;
    return 0;
}