Bottom Up Programming Question
wulfcry: Nice but you have to program the cells to contain the appearance of the duck the cells should know about and because that is a feature difficult to grasp it does not matter where you start. 
First design the beak put it in the cell
Design the webbed feet put it in the cell
Design the head put it in the cell 
Construct all cells and enumerate the cell based on the ducks feature 
And there you have it bottom up designed DUCK with out worry where to start.