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### Title

### Problem Statement

On a two-dimensional plane, there are `N` red points and `N` blue points.
The coordinates of the `i`-th red point are `(a _{i}, b_{i})`, and the coordinates of the

`i`-th blue point are

`(c`.

_{i}, d_{i})A red point and a blue point can form a *friendly pair* when, the `x`-coordinate of the red point is smaller than that of the blue point, and the `y`-coordinate of the red point is also smaller than that of the blue point.

At most how many friendly pairs can you form? Note that a point cannot belong to multiple pairs.

### Constraints

- All input values are integers.
`1 ≤ N ≤ 100``0 ≤ a`_{i}, b_{i}, c_{i}, d_{i}< 2N`a`are all different._{1}, a_{2}, ..., a_{N}, c_{1}, c_{2}, ..., c_{N}`b`are all different._{1}, b_{2}, ..., b_{N}, d_{1}, d_{2}, ..., d_{N}

### Input

Input is given from Standard Input in the following format:

Na_{1}b_{1}a_{2}b_{2}:a_{N}b_{N}c_{1}d_{1}c_{2}d_{2}:c_{N}d_{N}

### Output

Print the maximum number of friendly pairs.

### Sample Input 1

3 2 0 3 1 1 3 4 2 0 4 5 5

### Sample Output 1

2

For example, you can pair `(2, 0)` and `(4, 2)`, then `(3, 1)` and `(5, 5)`.

### Sample Input 2

3 0 0 1 1 5 2 2 3 3 4 4 5

### Sample Output 2

2

For example, you can pair `(0, 0)` and `(2, 3)`, then `(1, 1)` and `(3, 4)`.

### Sample Input 3

2 2 2 3 3 0 0 1 1

### Sample Output 3

0

It is possible that no pair can be formed.

### Sample Input 4

5 0 0 7 3 2 2 4 8 1 6 8 5 6 9 5 4 9 1 3 7

### Sample Output 4

5

### Sample Input 5

5 0 0 1 1 5 5 6 6 7 7 2 2 3 3 4 4 8 8 9 9

### Sample Output 5

4

### Tags

### Subtasks and Limits

Subtask | Score | #TC | Time | Memory | Scoring |
---|---|---|---|---|---|

1 | 100 | 20 | 2s | 256MB | Minimum |

2 | 0 | 5 | 2s | 256MB | Minimum |

### Judge Compile Command

g++-8 ans.cpp -o rbpoints -Wall -Wshadow -static -O2 -lm -m64 -s -w -std=gnu++17 -fmax-errors=512