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#0006B0

Space

Mrkvica, Terrifying space conqueror, Enslaver of worlds and Ruler of galaxies is once again on the move. This time the Delta galaxy has caught his seven eyes. His plan is to cruelly conquer three planets in Delta galaxy so that all the other planets would surrender without fighting.


The thing that Mrkvica doesn't like at all is presence of black holes somewhere in between the three recently conquered planets because it complicates the arrival and tourney of his favourite space-rock band across the new galaxy. Unfortunately for him, the Delta galaxy is full of black holes.


This is where you come in. Your job is to tell Mrkvica the number of different combinations of three planets such that the triangle formed by connecting these planets contains no black holes. All necessary data was prepared for you by Mrkvica's main strategist Rotkvica. Luckily for you, all planets and black holes are given as dots in plane and no three of them are collinear.



InputThe first line of input contains two integers N and M (0 \leq N, M \leq 500), the number of planets and the number of black holes in Delta galaxy, respectively.
Next N lines contain two integers which represent x and y coordinates of each planet.
Next M lines contain two integers which represent x and y coordinates of each black hole.
No coordinate is greater than 10^{9} by absolute value.


OutputWrite a single integer to the standard output - the number of different combinations of three planets such that the triangle formed by connecting these planets contains no black holes.


Input
4 2
0 0
5 4
10 10
10 0
2 1
9 3
Output
1


Input
3 1
-2 0
0 -2
3 3
0 0
Output
0

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