from math import sqrt
from collections import deque

N = int(input())

points = []
for _ in range(N):
    points.append(list(map(int, input().split())))

G = []    
for i in range(N):
    graph = []
    for j in range(i+1,N):
        distance = (points[i][0]-points[j][0])**2 + \
            (points[i][1]-points[j][1])**2
        if distance <= 100:
            graph.append(j)
    G.append(graph)

def dfs(start, end):
    distance = 0    
    visited = [False for _ in range(N)]

    que = deque()
    que.append(start)
    while len(que) != 0:
        adjacent = que.popleft()
        if adjacent == end:
            distance = sqrt((points[start][0]-points[adjacent][0])**2 + \
                (points[start][1]-points[adjacent][1])**2)
            break
        visited[adjacent] = True
        for point in G[adjacent]:
            if not visited[point]:
                que.appendleft(point)
    return distance

longest = 0
for i in range(N-1):
    for j in range(1,N):
        distance = dfs(i,j)
        longest = max(longest, distance)

if longest == 0:
    if len(points) == 0:
        print(1)
    else:
        print(2)
else:
    print(longest+2)