m just refers to the outermost variable in the algorithm on page 66. The point is that the Floyd-Warshall algorithm only needs 3 nested loops, not 4. - Cris On Feb 16, 2008, at 3:29 PM, Ricardo Villalon wrote: > Hi, > > In problem 3.27, what is "m"? > > Is it a typo or something we should know? > > Thanks > > Ricardo