//file1.h
#define USD 1
//file2.h
#define UKP 1
//file3
#include
#include
#ifdef USD
#define currency_rate 46
#endif
#ifdef UKP
#define currency_rate 100
#endif
main()
{
int rs;
rs = 10 * currency_rate;
printf ("%d\n", rs);
}