// Made By Haireden Aibyn
#include <algorithm>
#include <iostream>
#include <iomanip>
#include <cstring>
#include <cstdlib>
#include <fstream>
#include <string>
#include <cstdio>
#include <vector>
#include <cmath>
#include <ctime>
#include <queue>
#include <deque>
#include <stack>
#include <map>                   
#include <set>

using namespace std;

#define fname ""
#define INF 2147483647
#define MOD 1000000007
#define mp make_pair
#define F first
#define S second
#define sc scanf
#define pr printf
#define deb(x) cerr << " | " << #x << " = " << x
#define pb push_back
#define ex exit(0)
#define tim printf("%.4lf\n", (clock() * 1.) / CLOCKS_PER_SEC)
#define cas printf(""), ex;
#define y1 y4

typedef long long ll;
typedef unsigned long long ull;

const int N = 100500;

int h[N];

int main() {
    srand(time(NULL));
    for (int i = 0; i <= 'z' - 'a'; i++) {
        cin >> h[i];    
    }
    string s;
    cin >> s;
    int mx = 0;
    for (int i = 0; i < s.size(); i++) {
        mx = max(mx, h[s[i] - 'a']);    
    }
    cout << int(s.size()) * mx;
    #ifndef ONLINE_JUDGE
       cerr << clock() << " ms";
    #endif
    return 0;
}