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