C :: Creating PPM Image - Black Rectangle With A Circle

I'm trying to create a PPM image for a class assignment. A black rectangle with a circle at the point 225, 175 with a radius of 75. I have to use certain specific methods, so I can't use like Bresenham's really famous method for creating a circle.

The problem is that it compiles fine, and transfers to an image fine, but always says that I have a negative or zero image size.

Code:

#include "shapes.h"
int main () {
int i, j, x, y;

fprintf(stdout,"P6 width height 255
");

[Code] ....

And my header is:

Code:
#include <stdio.h>#include <math.h>
#define height 480
#define width 640
#define cy 175
#define cx 225
#define radius 75

The circle has to be filled in. I made it white. Also, i and j are unsused so far, so just ignore them.