#include <bits/stdc++.h>   using namespace std;   int main() {     int n1, n2, n3, n4;     long long ans;     unordered_map<char, int> m;     string s;     while (cin >> n1 >> n2 >> n3 >> n4) {       ans = 0;       m[ 1 ] = n1;       m[ 2 ] = n2;       m[ 3 ] = n3;       m[ 4 ] = n4;       cin >> s;       for (int i = 0; i < s.size(); i++) {         ans += m[s[i]];       }       cout << ans << endl;     }     return 0;   }   