#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>

using namespace std;


int main(){
    vector<int> count(26);
    for(int h_i = 0;h_i < 26;h_i++){
       cin >> count[h_i];
    }
    string word;
    cin >> word;
    int mx=INT_MIN;
    for(int i=0;i<word.length();i++)
        {
        if(count[word[i]-'a']>mx)
            mx=count[word[i]-'a'];
        
    }
    cout<<(word.length()*mx);
    return 0;
}