CSES - Intersection Points
  • Time limit: 1.00 s
  • Memory limit: 512 MB

Given nn horizontal and vertical line segments, your task is to calculate the number of their intersection points.

You can assume that no parallel line segments intersect, and no endpoint of a line segment is an intersection point.

Input

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

Then there are nn lines describing the line segments. Each line has four integers: x1x_1, y1y_1, x2x_2 and y2y_2: a line segment begins at point (x1,y1)(x_1,y_1) and ends at point (x2,y2)(x_2,y_2).

Output

Print the number of intersection points.

Constraints

  • 1n1051 \le n \le 10^5
  • 106x1x2106-10^6 \le x_1 \le x_2 \le 10^6
  • 106y1y2106-10^6 \le y_1 \le y_2 \le 10^6
  • (x1,y1)(x2,y2)(x_1,y_1) \neq (x_2,y_2)

Example

Input:

3
2 3 7 3
3 1 3 5
6 2 6 6

Output:

2