You are given co-ordinates of the boundary of a farm. The information about the farm are as follows:

• Building a single shelter costs 25 units.
• The farm lies in an \(infinite 2D\) plane.

You are required to write a program to calculate cost for building maximum number of shelters at some integral point strictly inside the fencing.

Input format

• First line contains a single integer N denoting number of logs used for fencing.
• Next N line contains two space-separated integers X and Y denoting the X and Y co-ordinates of the logs.
• Points are given in a counterclockwise direction.

Output format

Print the cost to build the maximum number of shelters.

Constraints
\(3 \le N \le 2 \times 10^5\)
\(1 \le X, Y \le 2 \times 10^6\)