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Articulation points - Timestamps

Articulation points - Timestamps

An undirected graph is given. Run a depth-first search from the given vertex v. Print the timestamps d[v] and up[v] for each vertex v in the increasing order of vertices.

Input

The first line contains the number of vertices n (n100) and edges m of an undirected graph. Each of the next m lines contains two vertices a and b - an undirected edge of the graph. The last line contains vertex v.

Output

Run dfs(v). Print the timestamps d[v] and up[v] for each vertex v (v = 1, 2, ..., n). The timestamps for each vertex must be printed on a separate line.

Hint

Use the adjacency matrix to get accepted.

prb10224.gif

Time limit 1 second
Memory limit 128 MiB
Input example #1
6 8
6 5
6 3
5 3
4 5
3 4
3 2
1 2
1 3
1
Output example #1
1 1
2 1
3 1
4 3
5 3
6 3
Input example #2
7 9
1 2
2 3
1 3
3 4
2 5
4 5
4 6
4 7
6 7
1
Output example #2
1 1
2 1
3 1
4 2
5 2
6 4
7 4