#include <bits/stdc++.h>
using namespace std;
int a, b, c, d, f, e;
int ans;
int main() {
  cin >> a >> b >> c >> d >> e >> f;
  if (e > f) {
    int sl1 = min(a, d);
    d = d - sl1;
    int sl2 = min(d, min(b, c));
    ans = sl1 * e + sl2 * f;
  } else {
    int sl2 = min(min(b, c), d);
    d -= sl2;
    int sl1 = min(a, d);
    ans = sl1 * e + sl2 * f;
  }
  cout << ans;
}
