#include <vector>
#include <list>
#include <map>
#include <set>
#include "queue"
#include <deque>
#include <stack>
#include <numeric>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <complex>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <cstring>
#include <climits>
#include <cassert>
#include <iostream>
#define MOD1 1000000007
inline void inp( long long int  &n ){n=0;int ch=getchar();int sign=1;while( ch < '0' || ch > '9' ){if(ch=='-')sign=-1; ch=getchar();}while( ch >= '0' && ch <= '9' )n = (n<<3)+(n<<1) + ch-'0', ch=getchar();n=n*sign;}
#define pi acos(-1)
#define pii pair<int,int>
#define vii vector<pii>
#define ll  long long int
#define loop(i,n) for(ll i=0;i<n;i++)
#define ll  long long int
#define LL long long int
#define loop2(i,n) for(ll i=1;i<=n;i++)
#define MIN(a,b) (a) < (b) ? (a) : (b)
#define MAX(a,b) (a) > (b) ? (a) : (b)
#define ABS(a) (a) > 0 ? (a) : -(a)
#define rep1(i,a,n) for(i=a;i<(n);i++)
#define pb push_back
#define ff first
#define ss second
#define mp make_pair
#define OUT_RT cerr << (float(clock()) / CLOCKS_PER_SEC) << endl
#define EPS 1e-9
#define ld long double
typedef std::tuple<int, int, int, int> query;
using namespace std;
//JAI SHREE KRISHNA
// Find the holy grail in an  adventure frought with danger
// The bigger the occasion, the better the response.
// Never giving in, fighting to the end
// Look at  the limits
// Check if it is binary search
// Code till the end ofcontest





int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    vector<ll>v1;
    loop(i, 26)
    {
        ll x;
        cin>>x;
        v1.pb(x);
    }
    ll max1 = -1;
    string z;
    cin>>z;
    ll y = z.length();
    loop(i, z.length())
    {
        max1 = max(max1,v1[z[i]-'a']);
    }
    
    cout<<max1*z.length();
    return 0;
}