Problems
Party Location
Party Location
After the programming contest, all of the contestants would like to throw a party. After the party, however, it will be late, and the contestants will be too tired to walk a long way home. In particular, each contestant refuses to come to the party if it is more than \textbf{2.5} km from his or her house.
The solution is to hold the party as close to as many of the contestants' houses as possible. This is where you come in: your job is to determine the optimal location for the party, so that as many contestants as possible will be willing to attend it.
We consider the city to be a flat square, \textbf{50} km on each side. A contestant can walk directly from the party in a straight line to his or her house (there are no obstacles).
\InputFile
Standard input consists of a number of lines, each containing two floating point numbers indicating the (\textbf{x}, \textbf{y}) coordinates of the house of one of the contestants. Each coordinate is between \textbf{0.0} and \textbf{50.0} (km). Each house is at a distinct location. There are at most \textbf{200} contestants.
\OutputFile
Standard output consists of a single integer: the maximum number of contestants that can attend the party.
Input example #1
4.0 4.0 4.0 5.0 5.0 6.0 1.0 20.0 1.0 21.0 1.0 22.0 1.0 25.0 1.0 26.0
Output example #1
4