#define NDEBUG

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <assert.h>
#include <math.h>

#include <list>
#include <set>
#include <map>
#include <vector>

using namespace std;

#undef max
#undef min
#define max(x,y) ((x)>(y)?(x):(y))
#define min(x,y) ((x)<(y)?(x):(y))

#ifdef NDEBUG
#define dprintf
#else
#define dprintf printf
#endif

int chomp(char *s)
{
	int len;
	
	len = strlen(s);
	while(len > 0 && (s[len-1] == '\r' || s[len-1] == '\n'))
		s[--len] = '\0';

	return len;
}

typedef struct {
	double x;
	double y;
} POINT;


POINT pt[300];
double dist[300][300];
int n;
POINT cen;



int main()
{
	int i,j;
	int ce1, ce2;   // circle edge
	double d;
	int m;  // max;
	int t;
	double dx, dy;
	
	while(1) {
		scanf("%d\n", &n);
		if (n == 0) break;
		for(i=0; i<n; i++) {
			scanf("%lf %lf\n", &pt[i].x, &pt[i].y);
		}
		if (n <= 1) {
			printf("%d\n", n);
			continue;
		}
#ifndef NDEBUG
		for(i=0; i<n; i++) {
			printf("%lf %lf\n", pt[i].x, pt[i].y);
		}
#endif
		// make distance table
		for(i=0; i<n; i++) {
			dist[i][i] = 0;
			for(j=i+1; j<n; j++) {
				dist[i][j] = dist[j][i] = sqrt((pt[i].x-pt[j].x)*(pt[i].x-pt[j].x)+(pt[i].y-pt[j].y)*(pt[i].y-pt[j].y));
			}
		}
		
		m = 0;
		for(ce1=0; ce1<n; ce1++) {
			for(ce2=ce1+1; ce2<n; ce2++) {
				if (dist[ce1][ce2] > 2.0) continue;
				// calc cen
				dx = pt[ce2].x-pt[ce1].x;
				dy = pt[ce2].y-pt[ce1].y;
				d = sqrt(dx*dx+dy*dy);
				cen.x = pt[ce1].x + (dx/2) + dy*(sqrt(1-d*d/4)/d);
				cen.y = pt[ce1].y + (dy/2) - dx*(sqrt(1-d*d/4)/d);
				// gather
				t=2;
				for(i=0; i<n; i++) {
					if (i == ce1 || i == ce2) continue;
					d = sqrt((cen.x-pt[i].x)*(cen.x-pt[i].x)+(cen.y-pt[i].y)*(cen.y-pt[i].y));
					if (d <= 1.0) {
						t++;
					}
				}
				m = max(m, t);
				// calc cen
				dx = pt[ce2].x-pt[ce1].x;
				dy = pt[ce2].y-pt[ce1].y;
				d = sqrt(dx*dx+dy*dy);
				cen.x = pt[ce1].x + (dx/2) - dy*(sqrt(1-d*d/4)/d);
				cen.y = pt[ce1].y + (dy/2) + dx*(sqrt(1-d*d/4)/d);
				// gather
				t=2;
				for(i=0; i<n; i++) {
					if (i == ce1 || i == ce2) continue;
					d = sqrt((cen.x-pt[i].x)*(cen.x-pt[i].x)+(cen.y-pt[i].y)*(cen.y-pt[i].y));
					if (d <= 1.0) {
						t++;
					}
				}
				m = max(m, t);

			}
		}
		if (m == 0)
			m = 1;
		
		printf("%d\n", m);
	}
	
	return 0;
}