#include<bits/stdc++.h>
using namespace std;
vector < string  >Split(string str)
{
    std::istringstream buf(str);
    std::istream_iterator<std::string> beg(buf), end;
    std::vector<std::string> tokens(beg, end);
    return tokens;
}

int main()
{
    vector < int > H(26);
    int i , j ;
    for(i=0;i<26;++i)
        cin>>H[i];
    string S;
    cin.ignore();
    getline(cin  , S);
    int ans = 0;
    vector < string > A = Split(S);
    for(auto &v:A)
    {
        int x = 0;
        for(int i=0;i<v.length();++i)
            x = max(x,H[v[i]-'a']);
        ans+=x * v.length();
    }
    cout<<ans;;
    return 0;
}