#include <bits/stdc++.h>
using namespace std;
int main() {
  int a[3], b[3];
  int k, d;
  cin >> a[0] >> a[1] >> a[2] >> k;
  for (int i = 0; i < 3; i++) {
    a[i]--;
    b[i] = 0;
  }
  sort(a, a + 3);
  for (int i = 0; i < 3; i++) {
    d = k / (3 - i);
    for (int j = i; j < 3; j++) {
      int t = min(a[j], d);
      b[j] += t;
      a[j] -= t;
      k -= t;
    }
  }
  cout << (long long)(b[0] + 1) * (b[1] + 1) * (b[2] + 1);
}
