**
Homework 4: Due 9/27
**

Add code to Ladders.java so that it outputs
all *connected components* of size 2 and size 3.
A *connected components* is a portion of the graph that is connected, but
is disconnected from the rest of the graph.
In Quiz 4(b) you were asked to enumerate the isolated vertices of the
ladders graph; these are the size-1 connected components of the graph.
A size-2 connected component would be pair of vertices
that have no neighbors other than each other.
A size-3 connected component can either be a path of length 2 that is
disconnected from the rest of the graph or a triangle that this disconnected
from the rest of the graph.

**Hint:** To enumerate all size-2 connected components, generate all pairs
of vertices using two nested for-loops and to
enumerate all size-3 connected components, generate all triples
of vertices using three nested for-loops.

Submit `Ladders.java` and a `Ladders.readme` file.