Problems
There are
Connecting two distinct points among them via the shortest distance forms a line segment.
Write a program that outputs the number of line segments parallel to the
Here, the term "parallel" is used to mean having the same slope.
Input
The first line contains an integer
The following
Output
In the first line, print the number of segments parallel to the
Hint: Since the answer may exceed the range of a 32-bit integer, it is recommended to use data types such as long long in C/C++ and long in Java.
Subtask
| # | Score | Condition |
|---|---|---|
| #1 | 15 | |
| #2 | 25 | |
| #3 | 60 | No additional constraints |
Example #1
5
2 4
3 3
1 3
2 1
1 1
4
Example #2
4
1 0
2 0
3 0
4 0
6