You are given a undirected unweighted graph.
Output the minimum number of edges need to be added to the graph so that , every pair of vertices has at least a even length path between them.
Imput:
A line denoting number of vertex n , and number of edges m . next m line contains the edges of the graph.
Output:
The minimum number of edges.followed by the edges
Sample input:
3 2
1 2
1 3
Output:
1
2 3