#include<stdio.h>
#include<math.h>
int main(){
  int n,i,j,l,max,c;
  double x[310],y[310],k,s,t,a,b,e=1e-6;
  while(scanf("%d",&n),n){
    max=1;
    for(i=0;i<n;i++)scanf("%lf %lf",&x[i],&y[i]);
    for(i=0;i<n;i++){
      for(j=i+1;j<n;j++){
	a=(x[i]-x[j])/2;
	b=(y[i]-y[j])/2;
	if(hypot(a,b)-e>1)continue;
	k=tan(acos(hypot(a,b)));
	s=x[j]+a+k*b;
	t=y[j]+b-k*a;
	for(l=c=0;l<n;l++){
	  if(hypot(x[l]-s,y[l]-t)-e<1)c++;
	}
	if(max<c)max=c;
	s=x[j]+a-k*b;
	t=y[j]+b+k*a;
	for(l=c=0;l<n;l++){
	  if(hypot(x[l]-s,y[l]-t)-e<1)c++;
	}
	if(max<c)max=c;
      }
    }
    printf("%d\n",max);
  }
  return 0;
}