#include <iostream>
#include <cstdio>
#include <string.h>
#include <algorithm>
#include <vector>
#include <string>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <sstream>
#include <cmath>
#include <ctime>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<string> vs;
typedef vector< vector<int> > vvi;
typedef vector<ll> vl;
typedef vector< vector<ll> > vvl;

#define forn(i, n) for (int i = 0; i < (int)(n); i++)
#define forv(i, v) forn(i, v.size())
#define all(v) v.begin(), v.end()
#define mp make_pair
#define pb push_back

int main() {
#ifdef NEREVAR_PROJECT
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif
    vi h(26);
    forn(i, 26) cin >> h[i];
    string s;
    cin >> s;
    int m = 0;
    forv(i, s) m = max(m, h[s[i] - 'a']);
    cout << m * s.size() << endl;
    return 0;
}