Given the following process tree:

In order to speed up the calculation, the program creates two child processes $($P$2$

and P $3).$ The communication between the parent process and the child processes

will be held through a pipe $($or pipes$).$ P$2$ calculates the multiplication of all

numbers from $1$ till n$/2-1,$ and writes the result into a pipe. P$3$ calculates the

multiplication of all numbers from N$/2$ till n $,$ and writes the result into a pipe. Then,

the parent process reads the result sent by the two child processes, and display the

factorial of n$.$ Note N is an integer number must be entered by the user.