#include<stdio.h>
#include<math.h>
#include<algorithm>
using namespace std;
double x[300],y[300];
double px[90000],py[90000];
int main(){
	int a;
	while(scanf("%d",&a),a){
		for(int i=0;i<a;i++)scanf("%lf%lf",x+i,y+i);
		int now=0;
		for(int i=0;i<a;i++){
			for(int j=i+1;j<a;j++){
				if((x[i]-x[j])*(x[i]-x[j])+(y[i]-y[j])*(y[i]-y[j])<4.0000001){
					double d=sqrt((x[i]-x[j])*(x[i]-x[j])+(y[i]-y[j])*(y[i]-y[j]));
					double mx=(x[i]+x[j])/2;
					double my=(y[i]+y[j])/2;
					double s=sqrt(1-d*d/4);
					double theta=atan((y[i]-y[j])/(x[i]-x[j]));
					px[now]=mx-sin(theta)*s;
					py[now++]=my+cos(theta)*s;
					px[now]=mx+sin(theta)*s;
					py[now++]=my-cos(theta)*s;
				}
			}
		}
		int ret=1;
		for(int i=0;i<now;i++){
			int k=0;
			for(int j=0;j<a;j++)if((px[i]-x[j])*(px[i]-x[j])+(py[i]-y[j])*(py[i]-y[j])<1.0000001)k++;
			ret=max(ret,k);
		}
		printf("%d\n",ret);
	}
}