#include <bits/stdc++.h>
using namespace std;
void Debug(vector<int> v) {
  for (int i : v) {
    cerr << i << " ";
  }
}
void Debug(int a[]) {
  for (int i = 0; i < 5; i++) {
    cerr << a[i] << " ";
  }
}
void Debug(int a) { cerr << a; }
void Debug(string a) { cerr << a; }
void Debug(long long a) { cerr << a; }
void Debug(unsigned long long a) { cerr << a; }
void Debug(float a) { cerr << a; }
void Debug(double a) { cerr << a; }
void Debug(char a) { cerr << a; }
int32_t main() {
  int64_t t;
  t = 1;
  while (t--) {
    int64_t t, s, v, j, e, f;
    cin >> t >> s >> v >> j >> e >> f;
    int64_t ans = 0;
    if (f > e) {
      ans += min(s, min(v, j)) * f;
      j -= min(s, min(v, j));
      ans += min(t, j) * e;
    } else {
      ans += min(t, j) * e;
      j -= min(t, j);
      ans += min(s, min(v, j)) * f;
    }
    cout << ans << "\n";
  }
  cerr << "Time Taken : " << (float)clock() / CLOCKS_PER_SEC << " secs"
       << "\n";
  return 0;
}
