#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c, d, e, f;
  cin >> a >> b >> c >> d >> e >> f;
  int t2 = min(b, c);
  int t1 = min(a, a);
  int ans = 0;
  for (int i = 0; i <= d; i++) {
    int tans = 0;
    tans += min(t1, i) * e;
    tans += min(t2, d - i) * f;
    ans = max(tans, ans);
  }
  cout << ans;
}
