main.c

this an OOP file which is very easy to understand. So, it is very suitable for the beginner to read.

#include <stdio.h>

#include "func1.h"

int
main( void )
{
    int a = func1(1,2) ;
    
    printf( "func2: %d\n" , func2( 10 ) ) ;
   
    return 0 ;
}