#include<bits/stdc++.h>
using namespace std;
#define fast ios_base::sync_with_stdio(false);cin.tie(NULL);
#define ull unsigned long long
#define ll  long long int
#define ff first
#define ss second
#define mp make_pair
#define pb push_back
#define pf push_front
#define ppb pop_back
#define ppf pop_front
#define ins insert
#define db double
#define ldb long double
#define it iterator
#define rit reverse_iterator
#define er equal_range
#define gcd __gcd
#define mod 1000000007
#define PI M_PI
#define fl(i,f,l) for(int i=f;i<=l;i++)
#define bl(i,l,f) for(int i=l;i>=f;i--)
#define sor(vv) sort(vv.begin(),vv.end())
#define rev(vv) reverse(vv.begin(),vv.end())
#define fin(vv,i) find(vv.begin(),vv.end(),i)
#define ub(vv,i) upper_bound(vv.begin(),vv.end(),i)
#define lb(vv,i) lower_bound(vv.begin(),vv.end(),i)

#define pi pair<int,int>
#define pl pair<ll,ll>
#define pis pair<int,string>
#define psi pair<string,int>
#define vpi vector<pi>
#define vpl vector<pl>
#define vpis vector<pis>
#define vpsi vector<psi>
#define vi vector<int>
#define vl vector<ll>
#define vii vector<int,int> 
#define vll vector<ll,ll>
#define qi queue<int> 
#define ql queue<ll> 
#define dqi deque<pi>
#define dql deque<pl>  
#define pqi priority_queue<int,vector<int>,greater<int> > 
#define pql priority_queue<long,vector<long>,greater<long> >
#define Y cout<<"YES\n"
#define N cout<<"NO\n"
#define yc cout<<"Yes\n"
#define nc cout<<"No\n"
#define ys cout<<"yes\n"
#define ns cout<<"no\n"
stringstream ss;
#define tc int t;cin>>t;while(t--)
#define C 10000005

int ma=INT_MIN;
ll mi=INT_MAX;
string s,s1,s2;
ll ans=0,res=0;

int main()
{
fast
//freopen("input.txt", "rt", stdin);
//freopen("ouput.txt", "wt", stdout);
int a[26];
fl(i,0,25)
cin>>a[i];
cin>>s;
int l=s.length();
fl(i,0,l-1)
{
ma=max(ma,a[s[i]-97]);
}
cout<<ma*l;
return(0);
}