#pragma region Header
#include <fstream>
#include <vector>
#include <string>
#include <algorithm>
#include <set>
#include <map>
#include <queue>
#include <iomanip>
#include <cstdlib>
#include <stdio.h>
#include <ctime>
#include <stack>
#include <sstream>
#include <iostream>
#include <functional> 
#include <unordered_map>
#include <unordered_set>
#define X first
#define Y second
#define mp make_pair
#define fid(n) for (int i = (n)-1;i>=0;i--)
#define fjd(n) for (int j = (n)-1;j>=0;j--)
#define fkd(n) for (int k = (n)-1;k>=0;k--)
#define fid1(n) for (int i = (n)-1;i>=1;i--)
#define fjd1(n) for (int j = (n)-1;j>=1;j--)
#define fkd1(n) for (int k = (n)-1;k>=1;k--)
#define fi(n) for (int i = 0;i<(n);i++)
#define fj(n) for (int j = 0;j<(n);j++)
#define fk(n) for (int k = 0;k<(n);k++)
#define fi1(n) for (int i = 1;i<(n);i++)
#define fj1(n) for (int j = 1;j<(n);j++)
#define fk1(n) for (int k = 1;k<(n);k++)
#define finc(a,b,c) for (int a = b; a < c; a++)
#define fdec(a,b,c) for (int a = b; a >= c; a--)
#define All(x) (x).begin(),(x).end()
#define rAll(x) (x).rbegin(),(x).rend()
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
using namespace std;
const ll linf = (1LL << 62) - 1;
const int inf = 1010101043;
void pause(bool a = true) {
#ifdef _DEBUG
	cerr << "PAUSE" << endl; string s; cin >> s;
#endif
}
ld PI = acos(-1);
template<class T>inline const T sqr(const T & x) { return x*x; }
template<class T>inline T dist(pair<T, T> a, pair<T, T> b) { return sqrt(sqr(a.X - b.X) + sqr(a.Y - b.Y)); }
template<class T>inline T prod(pair<T, T> a, pair<T, T> b, pair<T, T> c = mp(0, 0)) { return (a.X - c.X)*(b.Y - c.Y) - (a.Y - c.Y)*(b.X - c.X); }
template<class T>inline T prodv(pair<T, T> a, pair<T, T> b, pair<T, T> c = mp(0, 0)) { return (a.X - c.X)*(b.X - c.X) + (a.Y - c.Y)*(b.Y - c.Y); }
template<class T>inline bool intriangle(pair<T, T> a, pair<T, T> b, pair<T, T> c, pair<T, T> d) { return (abs(prod(a, b, c)) == abs(prod(a, b, d)) + abs(prod(a, c, d)) + abs(prod(b, c, d))); }
ll gcd(ll a, ll b) { while (b) { a %= b; swap(a, b); }return a; }
ll lcm(ll a, ll b) { return a*b / gcd(a, b); }
ll popcnt(ll mask) { ll cnt = 0; while (mask) cnt += mask & 1, mask >>= 1; return cnt; }
ull powi(ull a, ull b, ll mod = 1000000007) { if (b < 2) return b ? a : 1; return (powi((a*a) % mod, b / 2, mod)*(b % 2 ? a : 1LL)) % mod; }
template<class T> bool maxz(T & a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> bool minz(T & a, T b) { if (a > b) { a = b; return true; } return false; }
template<class T> bool maxze(T & a, T b) { if (a <= b) { a = b; return true; } return false; }
template<class T> bool minze(T & a, T b) { if (a >= b) { a = b; return true; } return false; }
ll mod7 = 1000000007; ll mod9 = 1000000009;
bool isprime(ll n) { if (n < 2) return 0; for (ll i = 2; i*i <= n; i++) if (n%i == 0) return 0; return 1; }
#pragma endregion



int main()
{
	ios::sync_with_stdio(false);cin.tie(0);
#ifdef _DEBUG
	ifstream cin("test.txt");
#endif
	vector<ll> h(26);
	fi(26) cin >> h[i];
	string s; cin >> s;
	ll ans = 0;
	fi(s.length()) ans = max(ans, (ll)s.length()*h[s[i] - 'a']);
	cout << ans << endl;
	pause(0); return 0;
}