#include<iostream>
#include<algorithm>
#include<vector>
#include<cmath>
#include<string>
#include<iomanip>
#include<climits>
#define FOR(i,a,b) for(int i=a;i<b;i++) 
#define ROF(i,a,b) for(int i=a;i>=b;i--)
#define vi vector<int>
#define vlli vector<long long int>
#define pb push_back
using namespace std;
int main(){
	vi height(26);
	FOR(i,0,26)
		cin>>height[i];
	string a;
	cin>>a;
	int max=INT_MIN;
	FOR(i,0,a.size()){
		if(height[a[i]-97]>max)
			max=height[a[i]-97];
	}
	cout<<max*a.size();	
}