Exercise $5-$ Programming with fork

Write a C program called sumfact.c that does the following:

Takes an integer argument $($say$,$ N$1)$ from the command line.

Forks two children processes

a$.$ First child computes $1+2+$dots$+N($sum of positive integers up to N $)$ and prints out the result

and its own identifier.

b$.$ Second child computes $1^{*}{2}^{*}$dots$*N($the factorial of N $)$ and prints out the result and its own

identifier.

Parent waits until both children are finished, then prints out the message "Done" and its own

identifier.

Sample execution $($assuming the executable is called sumfact$)$:

bash$$./$sumfact $5$

$[$ID $=101]$ Sum of positive integers up to $5$ is $15$

$[$ID $=102$ Factorial of $5$ is $120$

$ID=100$ Done

Help me about it please