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Description

Implement Breadth First Search algorithm, represent the input graphs using the data structures developed in lab 5.

Format

Submit a tar or zip file including a script named bfs.ml.

Input

The graph is undirected, unweighted graph.
First line is the number of edges.
Following lines are each edge u v.

Output

One line consists of the result. The starting point should always be 0.

Sample IO

Input

4
0 2
0 7
3 7
4 7

Output

0 2 7 3 4 

One edge that is input first, is expected to search first (edge 3 7 and 4 7 in this example).