#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, c, d, e;
  vector<int> precio, bus, carro;
  for (int i = 0; i < 4; i++) {
    cin >> a;
    precio.push_back(a);
  }
  cin >> b >> c;
  for (int j = 0; j < b; j++) {
    cin >> d;
    bus.push_back(d);
  }
  for (int k = 0; k < c; k++) {
    cin >> e;
    carro.push_back(e);
  }
  int suma = 0, suma2 = 0, suma3;
  for (int i = 0; i < b; i++) {
    int aux;
    aux = bus[i] * precio[0];
    if (aux > precio[1]) aux = precio[1];
    suma = suma + aux;
  }
  if (precio[2] < suma) suma = precio[2];
  for (int i = 0; i < c; i++) {
    int aux2;
    aux2 = carro[i] * precio[0];
    if (aux2 > precio[1]) aux2 = precio[1];
    suma2 = suma2 + aux2;
  }
  if (suma2 > precio[2]) suma2 = precio[2];
  suma3 = suma2 + suma;
  if (precio[3] < suma3)
    cout << precio[3] << endl;
  else
    cout << suma3 << endl;
  return 0;
}
