/* Sat Jul  3 16:22:06 JST 2004 */
/* Sat Jul  3 17:13:19 JST 2004 */
#include <stdio.h>
#include <math.h>

typedef struct {
  double x, y;
} point_t;

double EuclidDiff(point_t p1, point_t p2)
{
  return sqrt((p1.x - p2.x) * (p1.x - p2.x) + (p1.y - p2.y) * (p1.y - p2.y));
}

int main()
{
  int i, j, k, x, y, count, maxcount;
  point_t p[512], center, center2; int N;
  double base, oset, diff;

  while (1) {
    scanf("%d", &N); if (N == 0) { break; }
    for (i = 0; i < N; i++) { scanf("%lf %lf", &p[i].x, &p[i].y); }

    maxcount = count = 1;
    for (i = 0; i < N; i++) {
      for (j = i+1; j < N; j++) {
        base = atan2(p[j].y - p[i].y, p[j].x - p[i].x);
        if (2.0 < (diff = EuclidDiff(p[i], p[j]))) { continue; }
        oset = acos(diff / 2);

        center.x = p[i].x + cos(base - oset);
        center.y = p[i].y + sin(base - oset);
        count = 0;
        for (k = 0; k < N; k++) {
          if (EuclidDiff(center, p[k]) <= 1 + 0.000000001) {
            count++;
          }
        }
        if (maxcount < count) { maxcount = count; }

        center.x = p[i].x + cos(base + oset);
        center.y = p[i].y + sin(base + oset);
        count = 0;
        for (k = 0; k < N; k++) {
          if (EuclidDiff(center, p[k]) <= 1 + 0.00000001) {
            count++;
          }
        }
        if (maxcount < count) { maxcount = count; }
      }
    }
    printf("%d\n", maxcount);
  }
  return 0;
}