#include <fstream>
#include <iostream>
#include <string>
#include <complex>
#include <math.h>
#include <set>
#include <vector>
#include <map>
#include <queue>
#include <stdio.h>
#include <stack>
#include <algorithm>
#include <iomanip>
#include <list>
#include <ctime>
#include <memory.h>
#include <bitset>
#include <climits>
#include <iostream>
#include <stdlib.h>

#define F first
#define S second
#define endl "\n"
#define pb push_back
#define mp make_pair
#define bs 1000000007
#define pi 3.141592653589793
#define y1 kjdfshnvoavaofobiopj
using namespace std;

int found[30], maxx;
string st;

int main(){
//freopen("input.txt", "r", stdin);
ios_base::sync_with_stdio(0);
cin.tie(0);

for(int i = 0; i < 26; i++)
	cin>>found[i];
cin>>st;
for(int i = 0; i < st.size(); i++)
	maxx = max(maxx, found[st[i]-97]);
cout<<maxx*st.size()<<endl;

return 0;}