#!/usr/bin/env python
# -*- coding: utf-8 -*-
from decimal import Decimal
import math
from collections import deque

N = int(input())
XYs = [list(map(int,input().split())) for i in range(0,N)]
dist = lambda p1,p2: (p1[0] - p2[0])**2 + (p1[1] - p2[1])**2
distances = [[Decimal(dist(XYs[i], XYs[j])).sqrt() for i in range(N)] for j in range(N)]
max_distances = [10**10 for i in range(N)]
ans = 10**10

queue = deque([[0,0]])
while queue:
    distance,index = queue.popleft()
    if ans <= distance:
        continue
    if index == N-1:
        ans = min(ans,distance)
        continue
    for j in range(N):
        if index == j:
            continue

        if distances[index][j] < max_distances[j] and distance < max_distances[j]:
            max_distances[j] = max(distance,distances[index][j])
            queue.append([max_distances[j],j])


print(10*math.ceil(ans/10))