I am new to this platform please help me

#include <stdio.h>
int main(void) {
int X,Y,e;
float f;
scanf("%d",&X);
scanf("%d",&Y);
e=X%5;
if(0 < X<= 2000 && 0<= Y <= 2000 && X<Y && e==0){

    f=Y-X-0.50;
}
else{
    printf("%d",Y);
}
printf("Output %.2f",f);

 return 0;

}

This program is showing 0Output 0.00 in codechef.

Can you put the link of the problem.