/*--.--.--.--.--.--.--.--.--.--.--.--.--*
 *  	By-Anshal Dwivedi						 *
 *    IT , MNNIT Allahabad              *
 *		anshaldwivedi@gmail.com           *
 *--.--.--.--.--.--.--.--.--.--.--.--.--*/

#include <iostream>
#include <cstdio>
#include <vector>
#include <map>
#include <queue>
#include <stack>
#include <cstring>
#include <algorithm>
#include <cstdlib>
#include <cmath>
#include <set>
#include <limits.h>
#include <assert.h>
using namespace std;

#define mp make_pair
#define pb push_back
#define X first
#define Y second
#define null NULL
#define ll long long

#define tr(c, itr) for(itr = (c).begin(); itr != (c).end(); itr++)
#define present(container, element) (container.find(element) != container.end()) //for set,map,etc
#define cpresent(container, element) (find(all(container),element) != container.end()) //for vectors
#define all(c) c.begin(),c.end() //eg sort(all(v));
//Initialization
#define clr(a) memset(a,0,sizeof(a))
#define ini(a) memset(a,-1,sizeof(a))

//Input Output
#define inp(n) scanf("%d",&n)
#define inp2(n,m) inp(n), inp(m)
#define ins(s) scanf("%s",s)
#define inc(n) scanf("%c",&n)
#define inlf(n) scanf("%lf",&n)
#define inll(n) scanf("%lld",&n)
#define inll2(n,m) scanf("%lld%lld",&n,&m)

#define out(n) printf("%d\n",n)
#define out2(n,m) printf("%d %d\n",n,m)
#define outs(d) printf("%s\n",d)
#define sout(n) printf("%d ",n)
#define outll(n) printf("%lld\n",n)
#define soutll(n) printf("%lld ",n)
#define outll2(n,m) printf("%lld %lld\n",n,m)
#define nl printf("\n");

//loops
#define rep(i,n) for(int i=0;i<n;i++)
#define REP(i,a,b) for(int i=a;i<=b;i++)
#define PER(i,a,b) for(int i=b;i>=a;i--)

//const
#define MOD 1000000007
#define MOD_INV 1000000006
#define MAX 100009
#define INF 999999999
#define PI 3.14159265358979323846264338327

ll modpow(ll base, ll exp, ll modulus) {base %= modulus;ll result = 1;while (exp > 0){if (exp & 1) result = (result * base) % modulus;
base = (base * base) % modulus;exp >>= 1;}return result;}
int a[30];
int main()

{
	REP(i,0,25)
	{
		inp(a[i]);
	}
	getchar();
	char s[100];
	ins(s);
	int l=strlen(s);
	int mx=0;
	rep(i,l)
	{
		mx=max(a[s[i]-'a'],mx);
	}
	int ans=l*mx;
	cout<<ans<<endl;
	return 0;
}