//Author : pakhandi
//
using namespace std;

#include<bits/stdc++.h>

#define wl(n) while(n--)
#define fl(i,a,b) for(i=a; i<b; i++)
#define rev(i,a,b) for(i=a; i>=b; i--)

#define si(n) scanf("%d", &n)
#define sll(l) scanf("%lld",&l)
#define ss(s) scanf("%s", s)
#define sc(c) scanf("%c", &c)
#define sd(f) scanf("%lf", &f)

#define pi(n) printf("%d\n", n)
#define pll(l) printf("%lld\n", l)
#define ps(s) printf("%s\n", s)
#define pc(c) printf("%c\n", c)
#define pd(f) printf("%lf\n", f)

#define debug(x) cout<<"\n#("<<x<<")#\n"
#define nline printf("\n")

#define mem(a,i) memset(a,i,sizeof(a))

#define MOD 1000000007
#define ll long long int
#define u64 unsigned long long int

#define mclr(strn) strn.clear()
#define ignr cin.ignore()
#define PB push_back
#define SZ size
#define MP make_pair
#define fi first
#define sec second
string str1;

int arr[30];
int main()
{
	int i, j;

	fl(i,0,26)
		cin>>arr[i];

	cin >> str1;

	int h = 0;

	fl(i,0,str1.SZ())
		h = max(h, arr[str1[i] - 'a']);

	cout<<h*str1.SZ();


	return 0;
}
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