# I Hate Long Description

SELISE Coding Challenge 2...
Limits 1s, 512 MB

There are N cities in the country AjobDesh and M one way roads connecting the cities.

There lives exactly one AjobPrani in each of the N cities.
Every AjobPrani must visit at least one other AjobPrani if there is a path to visit. If possible then he should also return to his home town.

Find how many AjobPrani are unable to return to his home town.

## Input

First line contains the number of test cases T(1≤ T ≤10).

For each test case:

First line consists of two integers denoting N(1≤ N ≤100000) and M(0≤ M ≤200000).

Next M lines consist of two integers A and B denoting there is a directed road from A to B (1≤ A,B ≤N).The graph can contain self loops.

## Output

For every test case, you need to print “Case T: ” (where T is the test case number) followed by the number of AjobPrani who can't return.

## Sample

InputOutput
1
5 6
1 2
2 3
2 5
5 3
5 1
4 5
Case 1: 1

Route for each AjobPrani:
AjobPrani 1: 1->2->5->1
AjobPrani 2: 2->5->1->2
AjobPrani 3: no way to visit any other AjobPrani
AjobPrani 5: 5->1->2->5