Write a C program that corresponds to the below process tree. You are to use the fork() system call to create child processes. Additionally, your program should ensure that the parent processes wait for their child processes to complete. As you can see there are a total of 9 processes (including the parent process). Pa (PL (Pu Output: 1. Your program must print the pids of all the processes created on the screen. 2. Your program must ensure that duplicate pids are not printed. Sample Output: /lab3 7615 7616 7617 7618 7619 7620 7621 7622 7623