import numpy as np
from scipy.sparse.csgraph import connected_components
from scipy.spatial import distance

N = int(input())
P = np.array([tuple(map(int, input().split())) for _ in range(N)])
D = distance.cdist(P, P)


def f(x):
    _, labels = connected_components(D < x)
    return labels[0] == labels[-1]


# bisect
l, r = 0, 2 * 10 ** 9
while r - l > 10:
    m = (r + l) // 20 * 10
    if f(m):
        r = m
    else:
        l = m
print(r)