currency rate conversion Program by using pre-processor in C Language

currency rate conversion Program by using pre-processor in C Language

//file1.h
#define USD 1

//file2.h
#define UKP 1

//file3
#include 
#include     

#if (defined (USD))         
     #define currency_rate 46
#elif (defined (UKP))
     #define currency_rate 100   
#else
     # define currency_rate 1 
#endif            

 main()
{  
 int rs;
 rs = 10 * currency_rate;  
 printf (“%d\n”, rs);
}