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