#include <stdio.h>
#include <graphics.h>

#define START_X  100
#define START_Y   92
#define WallX     50
#define WallY      50
#define END_X   WallX * 4 + START_X
#define END_Y   WallY * 4 + START_Y

void delay(long t)
{
   long i,j;
   for(i=0; i<t; i++)
     for(j=0; j<60000; j++);
}

void main()
{
int gd = DETECT, gm, gerr ;
int x,y,c;

initgraph(&gd, &gm,"");
if((gerr = graphresult())!=0)
{
  printf("Graphic error : %s\n",grapherrormsg(gerr));
  exit(1);
}
       /* x end = 600, y end = 450 */

for(x=30; x<=100; x+=5)
{
   setcolor(WHITE);
   circle(x,30,25);
   delay(100);
   setcolor(BLACK);
   circle(x,30,25);
   if(x==100)
   {
     for(y=30; y<=450; y+=5)
      {
	setcolor(WHITE);
	circle(100,y,25);
	delay(100);
	setcolor(BLACK);
	circle(x,y,25);
	  if(y==450)
	    {
	     for(y=450; y>=210; y-=5)
	      {
	       setcolor(WHITE);
	       circle(105,y,25);
	       delay(100);
	       setcolor(BLACK);
	       circle(105,y,25);
	       if(x=105)
	       for(x=105; x>=115; x+=5)
	      {
	       setcolor(WHITE);
	       circle(x,210,25);
	       delay(100);
	       setcolor(BLACK);
	       circle(x,210,25);
	      }
	    }
       }
   }
}
}
getch();
closegraph();

}