#include <cmath>
#include <vector>
#include <iostream>
#include <limits>
#include <iostream>
#include <vector>
#include <cassert>
#include <map>
#include <cmath>
#include <set>
#include <algorithm>
#include <queue>

using namespace std;


int main(){

	vector<int> H(26);
	for(int &v : H)
		cin >> v;
	string S;
	cin >> S;
	int ma = 0;
	for(char c : S){
		ma = max(ma, H[c-'a']);
	}
	cout << (ma * S.size()) << endl; 
	
	
}


/*

7
voda
yoda
vina
boda
vona
beda
vino



 */