There are N cars placed along a (road) positive X-axis (say at co-ordinates x1=1, x2=5, x3=3 etc.)
Each car has a certain constant velocity (say v1=6, v2=3, v3=1 etc.).
If we just start this system at t=0, and keep it running till t=oo, what will be the total number of overtakes that will occur?
Input Format:
N # Number of test cases
P1 # Number of cars in the test case.
X1 V1 # Starting position of first car and velocity.
X2 V2 # Starting position of second car and velocity.
.
.
.
.
XP1 VP1 # Starting position of car P1 and velocity.
Example
SAMPLE INPUT
2
3
1 6
5 3
3 1
10
4 8
2 2
3 10
6 9
1 5
10 7
7 4
8 3
5 1
9 6
SAMPLE OUTPUT
2
22