//
//
// circular staircase
forever

{
	paper 0
      	pen 100
        line  90 97 98
	line 97 90 97 98
	line  80 97 88
	line 97 80 97 88
	line  80 95 88
	line 95 80 95 88
	set space 97
	repeat a 0 3
 	{		
		line  70 space 78
		line space 70 space 78
		set space (space -2)
	}
	set space 97
	repeat a 0 7
	{
	        line  60 space 68
	        line space 60 space 68
	        set space (space-2)
	}
	set space 97
	repeat a 0 15
	{
	        line  50 space 58
	        line space 50 space 58
	        set space (space-2)
	}
	set space 97
	repeat a 0 31
	{
	        line space 40 space 48
	        line  40 space 48
	        set space (space-2)
	}
	set space 97
	repeat a 0 63
	{
	 	line  30 space 38
	        line space 30 space 38
	        set space (space-2)
	}
	set space 1
	repeat a 0 31
	{
	        line  20 space 28
	        line space 20 space 28
	        set space (space +2)
	}
	set space 1
	repeat a 0 15
	{
	        line space 10 space 18
	        line  10 space 18
	        set space (space +2)
	}
	set space 1
	repeat a 0 7
	{
	        line  1 space 8
	        line space 1 space 8
	        set space (space +2)
	}
}