jsumabat is in another world! He is cultivating blobs in a field which can be represented by a cartesian plane.

There are ~N~ trees, and jsumabat plans to build a fence connected by each tree that can hold as many blobs as possible. Note that each blob requires at least 50 square meters of space to survive.

What is the maximum number of blobs that can survive if you make the largest possible field given your trees? Note that you do not need to use every tree.

Input Specification

The first line contains an integer ~N~ ~(1 \le N \le 10000)~, the number of trees. The next ~N~ lines contain the integer coordinates of the trees, ~x~ and ~y~, ~-1000 \le x, y, \le 1000~, where ~x~ and ~y~ are in metres.

Output Specification

Output a single integer, the number of blobs that can survive on the largest field you can construct using the available trees.

Sample Input 1

4
0 0
0 101
75 0
75 101

Sample Output 1

151