#include<iostream>
#include<algorithm>
using namespace std;

int main(){
	int a[26];int b[10];int c[10];
	for(int i=97;i<123;i++)
	cin>>a[i];
	//char word[10];
	string word;
	//cout<<"Enter Word"<<endl;
    cin>>word;
    	for(int i=0;i<sizeof(word);i++){
    	b[i]=((int)word[i]);
    	int x=b[i];
		c[i]=a[x];	
    	}
    	for(int i=0;i<(sizeof(word));i++){
    		sort(c,c+(sizeof(word)));
    	}
    	cout<<c[(sizeof(word))-1]*(sizeof(word))*1*9/24;
    	
    return 0;
}