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

#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define LL long long int
#define pb push_back 
#define mp make_pair
#define PII pair<int,int>
#define PLL pair<LL,LL>
#define PIS pair< int,string>	

#define VI vector <int>::iterator it;
#define VL vector <LL>::iterator lt;
#define VPI vector <PII>::iterator it;
#define VPL vector <PLL>::iterator plt; 

#define test int t;cin>>t;while(t--)
#define ff first
#define ss second
#define INF 1000000000
#define init(a,x) memset(a,x,sizeof(a))
#define input(a,n) for(i=0;i<n;i++)cin>>a[i];
#define output(a,n) for(i=1;i<=n;i++)cout<<a[i]<<" ";




int main() {
	fast 
	int n,m,i,j,k,z,x,y,sum=0,b,p,q,ans=0,h=0,l;
	bool f;
	string s;
	int a[26];
    input(a,26);
    cin>>s;
    l=s.length();
    for(i=0;i<l;i++)
        {
        h=max(h,a[s[i]-'a']);
    }
	cout<<l*h;
	return 0;
}