package test;import java.util.Arrays;import java.util.Scanner;
public classMain{
private long a =1;
private long b =1;
private long c =1;// 排序解决方案:
public long func(int x,int y ,int z,int k){int arry[]={x,y,z};
Arrays.sort(arry);int i;for(i =0;i < k;){if(a < arry[0]&& a == b){
a++;
i++;}elseif(c < arry[1]&& c == b){
c++;
i++;}elseif(b < arry[2]){
b++;
i++;}elsebreak;}
System.err.println(a+":"+b+":"+c);return a * b * c;}
public static void main(String[] args){
Scanner in= new Scanner(System.in);
Main main = new Main();while(in.hasNextInt()){int x =in.nextInt();int y =in.nextInt();int z =in.nextInt();int k =in.nextInt();
System.out.println(main.func(x,y,z,k));}}}