#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<vi> vvi;
typedef vector<vl> vvl;
typedef vector<double> vd;
typedef vector<vd> vvd;
typedef pair<int, int> pii;
typedef pair<double, double> pdd;
typedef vector<pii> vii;
typedef vector<string> vs;

int main(int argc, char const *argv[])
{
    ios_base::sync_with_stdio(false);
    
    /**gaand mara bhenchod**/

    int a[26];
    for(int i =0 ; i  <26; i++)
        cin >>a[i];
    string s;
    cin >> s;int max1 = 0;
    map<char,int> m;
    for(int i = 0 ; i < s.length();i++)
    {
        max1 = max(max1, a[s[i]-'a']);
        m[s[i]]++;
    }
    cout << s.length()*max1;

    return 0;
}