ATM Problem doubt

This is my code but i dont know what is wrong with it.
Link to problem : HS08TEST Problem - CodeChef

#include
#include
using namespace std;

int main()
{
int x;
float y,sum=0;
cin>>x>>y;
if(x>y)
{
cout<<fixed<<setprecision(2)<<y;
}
else if(x%5==0)
{
if(x>y)
{
cout<<fixed<<setprecision(2)<<y;
}
else if(x<y)
{
sum=y-x-0.50;
cout<<fixed<<setprecision(2)<<sum;
}
}
return 0;
}

I already explained the solution Here. Please notice that while you’re posting a topic, you will see some message in the right saying “Your topic is similar to…”, If you found any topic similar to yours and if that satisfies your doubt, do not create new topic.