// AUTHOR: ARVIND NAIR

#include<bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<int,int> pi;
typedef vector<int> vi;

#define TEST  int test_case; scanf("%d",&test_case); while(test_case--)
#define RT fprintf(stderr, "\nTIME = %lf\n", 1.0 * clock()/CLOCKS_PER_SEC);
#define rep(a,c)   for ( int (a)=0; (a)<(c); (a)++)
#define repn(a,b,c)  for ( int (a)=(b); (a)<=(c); (a)++)
#define repd(a,b,c)  for (  int (a)=(b); (a)>=(c); (a)--)
#define FOR(arr) for(auto &i:arr)
#define all(v) (v).begin(),(v).end()
#define fi  first
#define se  second
#define pb push_back
#define mp make_pair
#define EPS (double)(1e-9)
#define MOD 1000000007
#define M(x,i) memset(x,i,sizeof(x))
#define trace(x)    cout<<#x<<" is "<<x<<"\n"
#define sz(x) (int)(x.size())
#define si(n) scanf("%d",&n)
#define gi(n) printf("%d\n",n)
#define sll(n) scanf("%lld",&n)
#define gll(n) printf("%lld\n",n)

int a[30];

int main() {   

rep(i,26) si(a[i]);

string s; cin>>s;

int maxa=0;

rep(i,sz(s)) {

	  int p=s[i]-'a';
	  maxa=max(a[p],maxa);
}

 cout<<maxa*sz(s);
     
return 0;
}