#include <algorithm>
#include <complex>
#include <cstdarg>
#include <cstdio>
#include <cstdlib>
#include <functional>
#include <iomanip>
#include <istream>
#include <limits>
#include <map>
#include <numeric>
#include <ostream>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <string>
#include <tuple>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

// Powered by caide (code generator, tester, and library code inliner)
class Solution {
public:
    void solve(istream& in, ostream& out) {
        vector<int> h(26);
        for (int& i : h)
            in >> i;
        string s;
        in >> s;
        int m = 0;
        for (char c : s)
            m = max(m, h[c-'a']);
        out << m * s.length() << endl;
    }
};

void solve(istream& in, ostream& out)
{
    out << std::setprecision(12);
    Solution solution;
    solution.solve(in, out);
}

#include <fstream>
#include <iostream>

int main() {
    
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    istream& in = cin;

    ostream& out = cout;

    solve(in, out);
    return 0;
}