#include <bits/stdc++.h>

#define inf 0x7fffffff
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define all(c) c.begin,c.end
#define tr(c,it) for(typeof(c.begin())it=c.begin();it!=c.end();it++)
#define FOR(i,a,b) for(int i=a;i<b;i++)
#define mod 1000000007
#define gc getchar

using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int,int> ii;
typedef vector<ii> vii;
typedef queue<int> qi;

int main()
{
    vi a(26);

    FOR(i,0,26)cin>>a[i];

    string s;
    cin>>s;

    int mh=-1;

    for(int i=0;i<s.length();i++ ) 
    {
        mh=max(mh,a[s[i]-97]); 
    } 

    cout<<mh*s.length() ;
}