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(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):
    reached = []
    visited = [False for _ in range(N)]

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

longest = 0
for i in range(N):
    longest = max(longest, dfs(i))

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