#include <iostream>
#include <cstdio>
#include <cmath>

using namespace std;

int in_circle(double x, double y, const double *px, const double *py, int n)
{
  int i;
  int ret=0;
  for ( i=0 ; i<n ; i++ ) {
    double dx, dy;
    dx = x-px[i];
    dy = y-py[i];
    if ( dx*dx+dy*dy < 1.+1.e-8 )
      ret++;
  }
  return ret;
}

int main(void)
{
  double px[300], py[300];
  int n;
  int i, j;
  int p1, p2;
  int record;
  while ( scanf("%d", &n)==1 && n>0 ) {
    for ( i=0 ; i<n ; i++ ) {
      scanf("%lf%lf", &px[i], &py[i]);
    }
    record=1;
    for (p1=0 ; p1<n ; p1++ ) {
      for ( p2=p1+1 ; p2<n ; p2++ ) {
	double dx, dy;
	double cx, cy;
	cx = (px[p1]+px[p2])*.5;
	cy = (py[p1]+py[p2])*.5;
	dx = (-px[p1]+px[p2])*.5;
	dy = (-py[p1]+py[p2])*.5;
	double l = sqrt(dx*dx+dy*dy);
	if ( l>1. ) continue;
	double r = sqrt(1.-l*l);
	double drx, dry;
	drx = dy*r/l;
	dry = -dx*r/l;
	double rx, ry;
	rx = cx+drx;
	ry = cy+dry;
	i = in_circle(rx, ry, px, py, n);
	if ( i>record ) record=i; 
	rx = cx-drx;
	ry = cy-dry;
	i = in_circle(rx, ry, px, py, n);
	if ( i>record ) record=i;
      }
    }
    printf("%d\n", record);
  }
}