TSPAGAIN - Travelling Salesman Again !

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There are N cities numbered from 0..N-1. A salesman is located at city 0. He wishes to visit all cities exactly once and return back to city 0. There are K toll booths. Each toll booth has a certain range of functioning. The parameters for toll k are given as x_k and y_k. If the salesman travels from city i to j, he has to pay 1 dollar toll fee to each toll p having x_p >= i and y_p <= j. Calculate the cheapest way for the salesman to complete his tour.

Input :

The first line contains T the number of test cases. T test cases follow. The first line of each test case contains two space seperated integers N and K. Each of the next K lines contains 2 integers, the ith line containing x_i and y_i (0 <= x_i,y_i < N). A blank line seperates two test cases.

Output :

Output T lines, one for each test case, containing the required answer.

Sample Input :

3 2
2 0
0 2

3 4
1 0
2 1
0 1
1 2

Sample Output :


Constraints :

1 <= T <= 50
2 <= n <= 1000
1 <= K <= 10000

Added by:Varun Jalan
Time limit:0.430s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Resource:own problem used for Codechef APRIL10 contest