Write a program using conditional compilation directives to round off the number 56 to nearest fifties.Expected Output: 50

Write a program using conditional compilation directives to round off the number 56 to nearest fifties.Expected Output: 50

where is mistake?

#include <iostream>
using namespace std;
#define R 50
int main()
{
       int Div;
       Div = R % 50;
       cout<<"Div:: "<<Div;
       printf("\n");

#if(Div<=24)
{
       int Q;
       printf("Rounding down\n");
       Q =(int(R /50))*50;
       printf("%d",Q);
}
#else
{
       int Q;
       printf("Rounding UP\n");
       Q =(int(R/50)+1)*50;
       printf("%d",Q);
}
#endif
}