Largest Strongly Connected Component

You are given a directed graph representing a network of towns and roads. There are n towns numbered from 1 to n and m directed roads, each road going from town a to town b.

Your task is to compute the size of the largest strongly connected component (SCC) in the graph. A strongly connected component is a maximal subset of towns such that for every pair of towns u and v in the subset, there exists a directed path from u to v and from v to u. In mathematical terms, you are to find:

$$\text{SCC size} = \max_{\text{component}}\{ |\text{component}| \}\n $$

It is recommended to use Kosaraju's algorithm or any equivalent method to solve the problem efficiently.

inputFormat

The input is read from stdin and has the following format:

• The first line contains an integer T, the number of test cases.
• For each test case:
  • The first line contains two integers n and m where n is the number of towns and m is the number of roads.
  • Then follow m lines, each containing two integers a and b representing a directed road from town a to town b.

outputFormat

For each test case, output a single integer on a separate line to stdout representing the size of the largest strongly connected component in the graph.

## sample

1
5 5
1 2
2 3
3 1
4 5
5 4

3