Characterizing the network (I)

To start out, let's do some basic characterization of the network, by looking at the number of nodes and number of edges in a network. It has been pre-loaded as G and is available for exploration in the IPython Shell. Your job in this exercise is to identify how many nodes and edges are present in the network. You can use the functions len(G.nodes()) and len(G.edges()) to calculate the number of nodes and edges respectively.