New to programming and getting an error that I cannot figure out


I wrote the following simple program and am getting the subsequent error. I am jusrt learning and no doubt making a simple error. Need help. I created the a file named “book” under the pset1 directory. Thanks in advance.

#include <stdio.h>
int main(void)
int num;
printf("%d is the value of num", num);
return 0;

the error I am getting is this:
make: Nothing to be done for ‘book’