An edge in an undirected graph is a Bridge iff removing it disconnects the graph. You have to print all the Bridges of the given graph.
Input Format
First line contains two integers V and E. Each of next E line contains two integer u and v denoting an edge between vertex u and v.
Output Format
Print all the bridges.
Constraints
1 <= number of vertices(V) <= 1000 1 <= number of Edges(E) <= V*(V-1)/2;
Example
Input
5 5 0 1 0 2 2 1 2 3 4 3
Output
[[3, 4], [2, 3]]