#include <stdio.h>
#include <unistd.h>

int main()
{
    char pid[50];
    sprintf(pid, "%d", getpid());
    printf("Root PID: %d\n", getpid());
    if(fork() == 0)
	{
		printf("1 PID: %d\n", getpid());
		if(fork() == 0)
		{
			printf("11 PID: %d\n", getpid());
			sleep(2);
			return 0;
		}
		if(fork() == 0)
		{
		    printf("12 PID: %d\n", getpid());
		    sleep(2);
		    return 0;
		}
		sleep(2);
		return 0;
	}
	if(fork() == 0)
	{
		printf("2 PID: %d\n", getpid());
		if(fork() == 0)
		{
			printf("21 PID: %d\n", getpid());
			sleep(2);
			return 0;
		}
		if(fork() == 0)
		{
			printf("22 PID: %d\n", getpid());
			sleep(2);
			return 0;
		}
		sleep(1);
		execlp("pstree", "pstree", "-c", pid, (char *)NULL);
	}
	if(fork() == 0)
	{
		printf("3 PID: %d\n", getpid());
		if(fork() == 0)
		{
			printf("31 PID: %d\n", getpid());
			sleep(2);
			return 0;
		}
		if(fork() == 0)
		{
		    printf("32 PID: %d\n", getpid());
		    if(fork() == 0)
			{
				printf("321 PID: %d\n", getpid());
				sleep(2);
				return 0;
			}
		    sleep(2);
		    return 0;
		}
		sleep(2);
		return 0;
	}
	sleep(2);
	return 0;
}