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

main (){
	int pid1,pid2,pid3;
	pid1=fork();
	if(pid1==0)
               {
		printf("\n I love \n");
         	}
         else
	{
		printf("\n Operating System\n");
		pid2=fork();
		if (pid2==0)
		{
			printf("\n difficult \n");
			pid3=fork();
			printf("\n but interesting!!\n");
                }
		else
		{
		printf("\n class, \n");
		}
	}
}