#include <bits/stdc++.h>

#define pb(x) push_back(x);
#define in(y) insert(y);
#define tt(t) while(t--)
#define itr ::iterator it;
#define ll long long
#define vi vector<int>
#define ii pair<int, int>
#define vii vector<ii>
#define si set<int>                      
#define msi map<string, int>
#define new cout<<endl
#define ff(n) for(int i=0;i<n;i++)
#define all(v) sort(v.begin(),v.end())

using namespace std;

int main(){
    vector<int> mat(26);
    ff(26){
    	cin>>mat[i];
    }
    string s;
    cin>>s;
    int mx=0;
    ff(s.size()){
    	mx=max(mx,mat[s[i]-97]);
    }
    cout<<s.size()*mx<<endl;
    
    return 0;
}