//Archit Rai #include<bits/stdc++.h> using namespace std; #define pb push_back #define mp make_pair #define sz(a) (int)(a.size()) #define all(c) (c).begin(),(c).end() #define F first #define S second #define si(n) scanf("%d",&n) #define sll(n) scanf("%lld",&n) #define REP(i,a,b) for(int i=a;i<b;i++) #define MOD 1000000007 #define endl '\n' #define PIN(n) printf("%d\n",n) #define PLLN(n) printf("%lld\n",n) #define fast_io ios_base::sync_with_stdio(false);cin.tie(NULL) typedef long long int ll; #define N 100010 ll powmod(ll a,ll b) { if(b==0)return 1; ll x=powmod(a,b/2); ll y=(x*x)%MOD; if(b%2) return (a*y)%MOD; return y%MOD; } //Template ends here int a[26]; int main() { REP(i,0,26) cin>>(a[i]); int ans=0; string s; cin>>s; int m=0; REP(i,0,sz(s)) m=max(m,a[s[i]-'a']); cout<<m*sz(s)<<endl; return 0; }