#include <iostream>
#include <cstdio>
#include <queue>
#include <vector>
#include <algorithm>
#include <iomanip>
#include <stack>
#include <set>
#include <map>
#include <cmath>

#define forn(i,n) for(int i = 0; i < n; i++)
#define ford(i,n) for(long long i = n - 1; i > -1; i--)
#define forl(i,l,r) for(long long i = l; i <= r; i++)
#define forst(it, a, ll) for(set < ll > :: iterator it = a.begin(); it != a.end(); it++)
#define forld(i,l,r) for(long long i = l; i >= r; i--)
#define FAST_READ ios_base::sync_with_stdio(false);
#define in freopen("1.txt", "r", stdin);
#define out freopen("output.txt", "w", stdout);
#define MAXN 200010
#define INF 1000000000000000
#define MOD 1000000007
#define pi 3.14159265358973238462643383
#define EPS 0.00000001
#define f first
#define s second
#define rs resize
#define pb push_back
#define mp(i, j) make_pair(i, j)
#define COUT(n, a) fixed << setprecision(a) << n

using namespace std;

typedef unsigned long long ull;
typedef int long long ll;
typedef long double ld;
typedef string str;
typedef pair < ll, ll > pr;

int main()
{
    FAST_READ

    vector < ll > a(26);

    forn(i, 26)
    cin >> a[i];

    str b;

    cin >> b;

    ll mx = 0;

    forn(i, a.size())
    mx = max(a[b[i] - 'a'], mx);

    cout << mx * b.size() << endl;
}