#include <iostream>
#include <vector>
#include <set>
#include <algorithm>
#include <math.h>
using namespace std;

typedef pair<double,double> point;

double sq(double d){ return d*d; }

double dist(double x1,double y1,double x2,double y2)
{
  return sqrt(sq(x1-x2)+sq(y1-y2));
}

int intersect(point &pp,point &qq,
              double &cx1,double &cy1,
              double &cx2,double &cy2)
{
  double x1=pp.first,y1=pp.second,r1=1.0;
  double x2=qq.first,y2=qq.second,r2=1.0;

  double d=dist(x1,y1,x2,y2);

  double l,n,x,y,p,q;

  if ((d>r1+r2)||(d<fabs(r1-r2)))
    return 0;

  l=((r1*r1-r2*r2)/d+d)/2.0;

  n=sqrt(r1*r1-l*l);

  x=x1+(x2-x1)*l/d;
  y=y1+(y2-y1)*l/d;

  p=(y2-y1)*n/d;
  q=(x2-x1)*n/d;

  cx1=x+p;cx2=x-p;
  cy1=y-q;cy2=y+q;

  if (d==r1+r2) return 1;
  else return 2;
}

int solve(vector<point> &dat,double x,double y)
{
  int cnt=0;
  if (!(x>=0.0&&x<=10.0&&y>=0.0&&y<=10.0)) return 0;

  //  cout<<x<<","<<y<<endl;
  for (int i=0;i<dat.size();i++)
    if (dist(dat[i].first,dat[i].second,x,y)<=1.00001)
      cnt++;
  return cnt;
}

int sector(vector<point> &dat,double y)
{
  set<double> xs;
  int ret=0;
  for (int i=0;i<dat.size();i++){
    if (fabs(dat[i].second-y)>1)
      continue;
    double cod=sqrt(1-sq(fabs(dat[i].second-y)));
    xs.insert(dat[i].first+cod);
    xs.insert(dat[i].first-cod);
  }

  if (xs.size()==0) return 0;
  set<double>::iterator p=xs.begin();
  set<double>::iterator q=xs.begin();
  q++;
  while(q!=xs.end()){
    double x=((*p)+(*q))/2;
    ret=max(ret,solve(dat,x,y));
    p++;q++;
  }
  return ret;
}

int main(){
  for (;;){
    int n;
    cin>>n;
    if (n==0)
      break;

    vector<point> dat;
    set<point> cross;

    while(n--){
      double x,y;
      cin>>x>>y;
      point p=make_pair(x,y);

      for (int i=0;i<dat.size();i++){
        double cx1,cy1,cx2,cy2;
        int num=intersect(dat[i],p,cx1,cy1,cx2,cy2);
        if (num>=2) cross.insert(make_pair(cx2,cy2));
        if (num>=1) cross.insert(make_pair(cx1,cy1));
      }
      dat.push_back(p);
      cross.insert(p);
    }

    int ans=0;
    set<point>::iterator p=cross.begin();
    while(p!=cross.end()){
      ans=max(ans,solve(dat,p->first,p->second));
      p++;
    }
    cout<<ans<<endl;
  }
  return 0;
}