Problems

# Rectangles and nails

# Rectangles and nails

On the coordinate plane given **N** rectangles - kozhdy pair of opposite vertices, sides are parallel to coordinate axes and coordinates of the vertices - integers from the interval [**-50**, **50**]. What is the maximal number of rectangles can be nailed to the plane of a single nail? Rectangle is considered to be nailed, if a nail hammered into the inner point of the rectangle.

**Input**

The first line contains one number **N**. Further, there are **N** rows of **4** numbers - the coordinates of one of the diagonals of the rectangle.

**Output**

One number - the largest number of rectangles that can be nailed one nail.

Input example #1

4 -9 -11 -13 12 3 -3 -10 9 13 9 -12 10 9 6 -10 -8

Output example #1

3