#include <map>
#include <set>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <string>
#include <bitset>
#include <cstdio>
#include <limits>
#include <vector>
#include <climits>
#include <cstring>
#include <cstdlib>
#include <fstream>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <unordered_map>
#include<bits/stdc++.h>
#define ll long long int
using namespace std;


int main(){
    ll  a[200]={0};
    ll i,j,maximum=INT_MIN;
    for(i=97;i<=122;i++)
        {
        cin>>a[i];
       
}
    char s[20];
        cin>>s;
    for(i=0;s[i]!='\0';i++)
        {
        maximum = max(maximum,a[s[i]]);
    }
        cout<<maximum*strlen(s);
    return 0;
}