#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(){
    int n=26;
    vector<int> h(n);
    for(int h_i = 0;h_i < n;h_i++){
       cin >> h[h_i];
    }
    string word;
    cin >> word;
    int i=0;
    n=word.length();
    int ar=0;
    int max=0;
    int count=0;
    for(i=0;i<n;i++)
        if(word[i]==' '){
        ar+=max*count;
        max=0;
        count=0;}
    else{
        count++;
        if(h[word[i]-97]>max)
            max=h[word[i]-97];
    }
    ar+=max*count;
    cout<<ar;
    return 0;
}