#include <cstdio>
#include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <string>
#include <set>
#include <map>
#include <ctime>
#include <cstring>
#include <cassert>
#include <bitset>
#include <sstream>
#include <queue>

#define pb push_back
#define mp make_pair
#define fs first
#define sc second
#define sz(a) ((int) (a).size())
#define eprintf(...) fprintf(stderr, __VA_ARGS__)

using namespace std;

typedef long long int64;
typedef long double ldb;

const long double eps = 1e-9;
const int inf = (1 << 30) - 1;
const long long inf64 = ((long long)1 << 62) - 1;
const long double pi = acos(-1);

template <class T> T sqr (T x) {return x * x;}
template <class T> T abs (T x) {return x < 0 ? -x : x;}

int h[26];
string s;

int main () {
//  ios_base::sync_with_stdio(0);
//  freopen("input.txt", "rt", stdin);
//  freopen("output.txt", "wt", stdout);

    for (int i = 0; i < 26; ++i) {
        cin >> h[i];
    }
    cin >> s;

    int n = sz(s);
    int maxH = 0;
    for (int i = 0; i < n; ++i) {
        maxH = max(maxH, h[s[i] - 'a']);
    }

    cout << maxH * n << endl;

    return 0;
}