#include <bits/stdc++.h>

#define left nadnlassad
#define right asdaslknd
#define y1 kjdajasjdsas
#define nxt accepted
#define prev why_would_you_call_when_you_are_high

#define pb push_back
#define mp make_pair
#define mt make_tuple

#define f first
#define s second

#define ll long long
#define ld long double
#define ull unsigned ll

#define _hash pair<ll, ull>
#define pii pair<int, int>
#define uint unsigned int
#define puu pair<uint, uint>

#define sqr(x) ((x) * 1LL * (x))

#define vec vector<int>
#define sz(v) int(v.size())
#define all(v) v.begin(), v.end()
#define endl "\n"
#define _bits(x) __builtin_popcountll(x)

using namespace std;

void rf() {
    #define fname "sparse"
    #ifdef SONY
        freopen("input.txt", "r", stdin);
        //freopen("output.txt", "w", stdout);
    #else
        //freopen(fname".in", "r", stdin);
        //freopen(fname".out", "w", stdout);
    #endif //SONY
}

const int nx[8] = {2, -2, -2, 2, 1, 1, -1, -1};
const int ny[8] = {1, 1, -1, -1, 2, -2, -2, 2};
const int Nx[4] = {0, 0, -1, 1};
const int Ny[4] = {1, -1, 0, 0};

const ll LINF = (ll) 5e18;
const int INF = 1e9 + 7;

const int N = 6e5 + 1;
const int MAXN = 1e6 + 50;
const double EPS = 1e-9, PI = 3.14159265359;
int h[26];
string s;
  
int main() {
    srand(time(0));
    //ios_base::sync_with_stdio(0), cin.tie(0);
    rf();
    for (int i = 0; i < 26; i++) cin >> h[i];
    cin >> s;
    int ans = h[s[0] - 'a'];
    for (auto i : s) {
        ans = max(ans, h[i - 'a']);
    }
    cout << ans * 1LL * sz(s);
    return 0;
}