$4.$a Consider the following C program.i$.$ Describe as precisely as you can the meaning of the code on the following lines:

Line $4$

Line $6$

Line $9$

Line $27$

Line $29$

ii$.$ Why are there so few curly $\{\}$ brackets in this program?

$[5$ marks$]$

iii. 'Dry run' the program starting at line $22.$ Describe the logical flow of execution of the program using the line numbers to help.

iv$.$ What is the purpose of the program? What does the program print as a result?