#include <stdlib.h>
#include <stdio.h>
#include <math.h>

#define DIM_X 500
#define DIM_Y 500

int main() {
    FILE *image_file;
    int i, j;
    int red, green, blue;

    image_file = fopen("im.pnm", "wb");

    fprintf(image_file, "P6\n");
    fprintf(image_file, "%d %d\n", DIM_X, DIM_Y);
    fprintf(image_file, "255\n");

    for (i = 0; i < DIM_X; i++)
        for (j = 0; j < DIM_Y; j++)
        {
            red = abs(floor(sin(i)*750 + sin(j)*750)) % 256;;
            green = 0;
            blue = 0;
            fputc(red, image_file);
            fputc(green, image_file);
            fputc(blue, image_file);
        }

    fclose(image_file);
    return 0;
}