/**
 *  Circle and Points (PKU 1981)
 *  by Kenji Inoue, 2007-01-05
 **/

#include <iostream>
#include <math.h>

using namespace std;

#define EPS (1e-6)

double x[300], y[300];

int sign[] = {+1, -1};

int main(void) {
  int n;
  while (cin >> n, n) {
    for (int i=0; i<n; i++) {
      cin >> x[i] >> y[i];
    }

    int ans = 1;
    for (int i=0; i<n; i++) {
      for (int j=i+1; j<n; j++) {
        double d = hypot(x[i]-x[j], y[i]-y[j]);
        if ( d > 2.0 + EPS ) { continue; }

        double mx = (x[i] + x[j]) / 2;
        double my = (y[i] + y[j]) / 2;
        double vx = (x[j] - x[i]) / d;
        double vy = (y[j] - y[i]) / d;
        double e = sqrt(1.0 - d*d/4.0);

        for (int s=0; s<2; s++) {
          double px = mx + sign[s]*e*vy;
          double py = my - sign[s]*e*vx;

          int cnt = 2;
          for (int k=0; k<n; k++) {
            if (k==i || k==j) { continue; }
            if ( (px-x[k])*(px-x[k]) + (py-y[k])*(py-y[k]) < 1.0 + EPS ) { cnt++; }
          }
          if (cnt > ans) { ans = cnt; }
        }
      }
    }

    cout << ans << endl;
  }
  return 0;
}