div(8,4,1)
 div(7,3,1)         	1 ....
  div(6,2,1)		1 1 ...
   div(5,1,1)		1 1 1 ...
5			1 1 1 5
   div(4,1,2)		1 1 2 ...
4			1 1 2 4
   div(3,1,3)		1 1 3 ...
3			1 1 3 3
  div(5,2,2)		1 2 ....
   div(3,1,2)		1 2 2 ...
3			1 2 2 3
 div(6,3,2)		2 ...
2 2 2			2 2 2 2