POSTERS  Election Posters
A parliamentary election was being held in Byteland. Its enterprising and orderly citizens decided to limit the entire election campaign to a single dedicated wall, so as not to ruin the panorama with countless posters and billboards. Every politician was allowed to hang exactly one poster on the wall. All posters extend from top to bottom, but are hung at different points of the wall, and may be of different width. The wall is divided horizontally into sections, and a poster completely occupies two or more adjacent sections.
With time, some of the posters were covered (partially or completely) by those of other politicians. Knowing the location of all the posters and the order in which they were hung, determine how many posters have at least one visible section in the end.
Input
The input begins with the integer t, the number of test cases. Then t test cases follow.
Each test case begins with a line containing integer n  the number of posters (1 <= n <= 40000). Then n lines follow, the ith (1 <= i <= n) containing exactly two integers l_{i} r_{i}, denoting the numbers of the leftmost and rightmost sections covered by the ith poster (1 <= l_{i} < r_{i} <= 10^{7}). The input order corresponds to the order of hanging posters.
Output
For each test case output a line containing one integerĀ  the number of posters with visible sections.
Example
Sample input: 1 5 1 4 2 6 8 10 3 4 7 10 Sample output: 4
An illustration of the sample input is given below.
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coding_express:
20130518 21:19:51
more test cases please 

coding_express:
20130518 21:19:05
please give some tricky test cases 

昌(尼莫):
20130515 03:31:04
i am constantly getting WA but i tried various test cases and it seems to be working fine . So , if there are any good cases please help me 

saket diwakar:
20130118 21:44:37
nice one.....:) Last edit: 20130201 03:51:38 

Paul Draper:
20121120 04:36:17
A good test case that I failed on at first


Brian Bi:
20101115 02:33:46
The judge is occasionally buggy in this way. If it bothers you that much, you can contact the problem setter and ask him to rejudge it... 

shivmitra mishra:
20100730 21:16:36
there is an AC solution using 0.00 sec and 0k memory..hws that possible while other solutions have used memory like 2.0 M ???? 
Added by:  adrian 
Date:  20040719 
Time limit:  7s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All 
Resource:  VI Polish Collegiate Team Programming Contest (AMPPZ), 2001 