Kill Captain America
Hard Accuracy: 20.39% Submissions: 1525 Points: 8

Captain America is hiding from Thanos in a maze full of rooms.
The maze is designed in such a way that the room, within it, leads to another room via gate. Captain America is hiding only in those rooms which are accessible directly/indirectly through every other room in the maze.
Further provided that, the movement from one room (R1) to another room (R2) is one way(unidirectional) only .
Now, you being on Thanos side, want to kill Captain America.  

First line of the input contains T, the number of test cases.
First line of each test case contains n(no of rooms) and m(no of gates).
Each m line of test case contains p and q denoting room p is connected to room q .

Each new line of the output contains Total no of rooms .

1 ≤ T ≤ 100
1 ≤ n ≤ 30000
1 ≤ m ≤ 200000
1 ≤ p,q ≤ n


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




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