Write a program that reads a graph from the console and determines whether the graph is connected. The

first line in the input contains a number that indicates the number of vertices $($n$).$ The vertices are labeled as

$0,1,...,$ n$-1.$ Each subsequent line, with the format u v$1$ v$2...,$ describes edges

$($u$,$ v$1),($u$,$ v$2),$ and so on$.$ Figure $26\mathrm{.}18$ gives the examples of two input for their corresponding

graphs.