#include <bits/stdc++.h>

#define F first
#define S second

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

#define pb push_back
#define ppb pop_back
#define mp make_pair

#define sz(x) (int) x.size()
#define all(x) x.begin(), x.end()
#define bit(x) __builtin_popcountll(x)
#define sqr(x) ((x) * 1LL * (x))

#define nl '\n'
#define ioi exit(0);

#define NeedForSpeed ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);

using namespace std;

typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
typedef pair <double, double> pdd;

const int N = 1e5 + 7, MxN = 1e6 + 7, mod = 1e9 + 7, inf = 2e9 + 7;
const long long linf = 1e18 + 7;
const double eps = 1e-9;
const int ii[] = {-1, 0, 1, 0}, jj[] = {0, 1, 0, -1};

    int mx;
    int a[256];
    string s;
int main(){
    for (int i = 'a'; i <= 'z'; i++)
        cin >> a[i];
    cin >> s;
    for (int i = 0; i < sz(s); i++){
        mx = max(mx, a[s[i]]);
    }
    cout << sz(s) * mx;
    ioi
}