lengths favorite prefix code who a previous code we can build a tree look at a tree we can look at the tree will actually end initially over here at those red dots because that's where the code words are but we expand the tree to be of equal depth everywhere so even though maybe your symbol a would be encoded here you continue because you want to make it all equal death then after you've done that you can do a simple count you can say each code word for example this one over here how many leaves are covered by it well the whole