Please don't hand write.

The complete bipartite graph Km,\" where m, n E 1, has 17.: red nodes, n blue nodes and has an edge between every red node and ever},r blue node. There are no edges between nodes of the same color. For illustration, here is K33: B B R R R [a] Let D be the number of edges of Km,\" that we have to delete from the graph to obtain a spanning tree. Prove that D is divisible by m 1. {b} Assume that m 3* n. Prove that the length of a longest path in Kmm is even