#include <iostream>
#include <vector>
#include <string>
#include <math.h>
#include <algorithm>
#include<set>
#include <unordered_map>
#include<map>

#define ll long long
#ifdef DEBUG
#define PN(n) cout<<" "<<#n<<" "<<n<<endl;
#define P(n) cout<<" "<<#n<<" "<<n;
#else
#define PN(n) ;
#define P(n) ;
#endif

using namespace std;


// input multiple integers
int n , m , x ;
// loop variables
int l1 , l2 , l3;
// integer array
int arr1[100005] ;
//string
string str;
//vector
vector<int> varr;
int vint;
// char array
char carr[1000];

int main () {

        // one input - int array
        for ( l1 = 0 ; l1 < 26; l1++ ) {
                cin>>arr1[l1];
        }
        cin>>str;
        for ( l1 = 0 ; l1 < 26; l1++ ) {
                m  = max(m,arr1[str[l1]-'a']);
        }
        m = m*str.size();
        cout<<m<<endl;

}