/*****************************
Coded by : return007
Copyright 2016. All Rights Reserved.
*****************************/

#include <bits/stdc++.h>
using namespace std;

//STL
#define MP make_pair
#define PB push_back
#define X first
#define Y second

//Datatypes
typedef long long ll;
typedef vector<int> vi;
typedef vector< vi > vvi;

//Loops
#define loop(i,n) for(int i=0;i<n;i++)
#define upto(n) while(n--)
#define LOOP(i,a,b) for(int i=a;i<=b;i++)

//Input
#define sd(x) scanf("%d",&x);
#define sld(x) scanf("%ld",&x);
#define slld(x) scanf("%lld",&x);
#define ss(x) scanf("%s",x);
#define gc getchar_unlocked();
#define s2d(x,y) scanf("%d%d",&x,&y);
#define s2lld(x,y) scanf("%lld%lld",&x,&y);
#define sarr(x,n) for(int i=0;i<n;i++) sd(x[i])
#define zeros(x,n) for(int i=0;i<n;i++) x[i] = 0;
#define init(x,n,val) for(int i=0;i<n;i++) x[i] = val;
int fastInt(){
	int x = 0;
	char ch;
	while((ch = getchar_unlocked())!= '\n' && ch != ' ' && ch != '\0'){
		x = x*10+ch-'0';
	}
	return x;
}

//Output
#define pd(x) printf("%d\n",x);
#define pld(x) printf("%ld\n",x);
#define plld(x) printf("%lld\n",x);
#define ps(x) printf("%s",x);
#define pc(x) putchar_unlocked(x);
#define pnl printf("\n");
#define parr(x,n) for(int i=0;i<n;i++) pd(x[i])

//Others
#define MOD 1000000007
#define INF 999999999999999
#define IINF INT_MAX
#define SIZE 1000009

ll modExp(ll a, ll b){
	if(b == 0)
		return 1;
	ll ans = modExp(a,b/2);
	ans = (ans*ans)%MOD;
	if(b%2)
		ans = (ans*a)%MOD;
	return ans;
}

int main(){
	int i,j,k,l,n,m,t;
	int arr[50];
	sarr(arr,26);
	char str[100];
	ss(str);
	l = strlen(str);
	int max = 0;
	for(i=0;i<l;i++){
		if(arr[str[i]-'a'] > max)
			max = arr[str[i]-'a'];
	}
	pd(max*l)
}