Since the number of different st-paths is exponential, we wish to generate a set of paths that have high probability to correspond to real quasispecies sequences. In order to estimate path probability, we independently estimate for each edge e the probability p(e) that it connects two reads from the same quasispecies, and then multiply estimated probabilities for all edges on the path. Under the assumption of independence between edges, if we assign to each edge e a cost equal tolog (p(e)) = log(1/p(e)), then the minimum-cost st-path will have the maximum probability to represent a quasispecies sequence.