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

#include <iostream>
#include <complex>
#include <queue>

using namespace std;

typedef complex<double> P;

#define EPS (1e-6)
double R2 = sqrt(2.0);

int n;
P p[300];

struct box {
  double x, y, size;
  int cnt;

  bool operator<(const box &a) const {
    return (cnt < a.cnt);
  }
};
priority_queue<box> pq;
int ans;

void push(double x, double y, double size) {
  box b = {x, y, size, 0};

  int cnt = 0;
  P c = P(x + size/2.0, y + size/2.0); // center point
  //double er = R2*size + 1.0; // radius of external circle
  double er = (R2*size + 1.0) * (R2*size + 1.0);
  for (int i=0; i<n; i++) {
    //double d = abs(c - p[i]);
    P tmp = c - p[i];
    double d = tmp.real()*tmp.real() + tmp.imag()*tmp.imag();
    if (d < 1.0 + EPS) { cnt++; }
    if (d < er + EPS) { b.cnt++; }
  }

  if (cnt > ans) { ans = cnt; }
  if (b.cnt > ans) { pq.push(b); }
}

int main() {
  while (cin >> n, n) {
    for (int i=0; i<n; i++) {
      cin >> p[i].real() >> p[i].imag();
    }

    // while (!pq.empty()) { pq.pop(); }
    box first = {0.0, 0.0, 10.0, n};
    pq.push(first);

    ans = 1;
    while (!pq.empty()) {
      box b = pq.top();
      pq.pop();

      if (b.cnt > ans) {
        double half = b.size / 2.0;
        push(b.x, b.y, half);
        push(b.x+half, b.y, half);
        push(b.x, b.y+half, half);
        push(b.x+half, b.y+half, half);
      }
    }

    cout << ans << endl;
  }

  return 0;
}