Save makefile$-$double$\mathrm{.}2.$ Add the following include statement at the top of your program: #include "getdouble.h$"3.$ Define and use at least $1$ symbolic constant with #defineIt is up to you to decide what you want to be a constant. You may need to come back to this bullet later$\mathrm{.}4.$ Useatleast$1$puts$()$functioncall$.$It is up to you what you want to print using puts$()\mathrm{.}5.$ Use int for all numeric variable types, this will make the calculations and output simpler$\mathrm{.}6.$ Output a message telling the user what this program does$\mathrm{.}7.$ Ask the user to enter their birth year$\mathrm{.}8.$ Usethecustomgetdouble$()$functiontogetthebirthyearandstoretheyearinanintvariable$.$Typecast the return value to store it in an int variable. For example:birthYear $=($int$)$ getdouble$()$;