#abc224c. [abc224_c]Triangle?

[abc224_c]Triangle?

Problem Statement

In the xyxy-plane, we have NN points numbered 11 through NN.
Point ii is at the coordinates (Xi,Yi)(X_i,Y_i). Any two different points are at different positions.
Find the number of ways to choose three of these NN points so that connecting the chosen points with segments results in a triangle with a positive area.

Constraints

  • All values in input are integers.
  • 3leNle3003 \\le N \\le 300
  • \-109leXi,Yile109\-10^9 \\le X_i,Y_i \\le 10^9
  • (Xi,Yi)neq(Xj,Yj)(X_i,Y_i) \\neq (X_j,Y_j) if ineqji \\neq j.

Input

Input is given from Standard Input in the following format:

NN X1X_1 Y1Y_1 X2X_2 Y2Y_2 dots\\dots XNX_N YNY_N

Output

Print the answer as an integer.


Sample Input 1

4
0 1
1 3
1 1
-1 -1

Sample Output 1

3

The figure below illustrates the points.

There are three ways to choose points that form a triangle: 1,2,3,1,3,4,2,3,4\\{1,2,3\\},\\{1,3,4\\},\\{2,3,4\\}.


Sample Input 2

20
224 433
987654321 987654321
2 0
6 4
314159265 358979323
0 0
-123456789 123456789
-1000000000 1000000000
124 233
9 -6
-4 0
9 5
-7 3
333333333 -333333333
-9 -1
7 -10
-1 5
324 633
1000000000 -1000000000
20 0

Sample Output 2

1124