**Time limit:**1.00 s**Memory limit:**512 MB

You may assume that no parallel line segments overlap, and no two line segments have a common endpoint.

**Input**

The first input line has an integer $n$: the number of line segments.

Then there are $n$ lines describing the line segments. Each line has four integers: $x_1$, $y_1$, $x_2$ and $y_2$: a line segment begins at point $(x_1,y_1)$ and ends at point $(x_2,y_2)$.

**Output**

Print the number of intersection points.

**Constraints**

- $1 \le n \le 10^5$

- $-10^6 \le x_1 \le x_2 \le 10^6$

- $-10^6 \le y_1 \le y_2 \le 10^6$

**Example**

Input:

`3`

2 3 7 3

3 1 3 5

6 2 6 6

Output:

`2`