you associate with it a weight P I which is the probability of that symbol from there you repeat the same process over and over until it's all connected together in a single tree what is this process you selected two trees with min probabilities P kmpl initially when each symbol is its own thing what that means is you find the two symbols with the lowest probability later on once you've done some merges it'll be the trees that at the root have the lowest problem then you merge those two into a single tree with associated probability as the sum