i want to know why it is wrong answer

#include<stdio.h>

int main()
{
int x;
float y;

scanf("%d",&x);
scanf("%f",&y);
if(x>0&&x<=2000)
{
	if(x%5==0)
	{


		if(y>x)
		{
			if(y>=0&&y<=2000)
			{
				printf("%0.2f",y=y-x-0.5);

			}
			else
			{

				printf("%f",y);
			}

		}
		else
		{

			printf("%0.2f",y);
		}

	}
	else
	{

		printf("%0.2f",y);
	}


}
else
{

  printf("0.2%f",y);
}

return 0;

}

//