Returns true if the the two sites are in the same component.

Returns the component identifier for the component containing site p.

Reads in a an integer N and a sequence of pairs of integers (between 0 and N-1) from standard input, where each integer in the pair represents some site; if the sites are in different components, merge the two components and print the pair to standard output.

Merges the component containing site p with the the component containing site q.