#!/usr/bin/env python3.8
# %%
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
import itertools

# %%
N = int(readline())
m = map(int, read().split())
XY = tuple(zip(m, m))


# %%
def gen_edges():
    for i, j in itertools.combinations(range(N), 2):
        x1, y1 = XY[i]
        x2, y2 = XY[j]
        dx = x1 - x2
        dy = y1 - y2
        if dx * dx + dy * dy <= 100:
            yield(i, j)


# %%
class UnionFind:
    def __init__(self, N):
        self.root = list(range(N))
        self.size = [1] * (N)

    def find_root(self, x):
        root = self.root
        while root[x] != x:
            root[x] = root[root[x]]
            x = root[x]
        return x

    def merge(self, x, y):
        x = self.find_root(x)
        y = self.find_root(y)
        if x == y:
            return False
        sx, sy = self.size[x], self.size[y]
        if sx < sy:
            self.root[x] = y
            self.size[y] += sx
        else:
            self.root[y] = x
            self.size[x] += sy
        return True


# %%
uf = UnionFind(N)
for i, j in gen_edges():
    uf.merge(i, j)


# %%
root = [uf.find_root(i) for i in range(N)]


def gen_dist():
    for i, j in itertools.combinations(range(N), 2):
        if root[i] == root[j]:
            x1, y1 = XY[i]
            x2, y2 = XY[j]
            dx = x1 - x2
            dy = y1 - y2
            yield (dx * dx + dy * dy) ** .5


# %%
answer = max(gen_dist(), default=0) + 2
if N == 0:
    answer = 1
print(answer)