from collections import deque
class UnionFind:
    def __init__(self, sz):
        self.par = [-1] * sz

    def root(self, pos):
        if self.par[pos] < 0:
            return pos
        self.par[pos] = self.root(self.par[pos])
        return self.par[pos]

    def unite(self, u, v):
        u = self.root(u)
        v = self.root(v)
        if u == v:
            return
        self.par[u] += self.par[v]
        self.par[v] = u

    def same(self, u, v):
        if self.root(u) == self.root(v):
            return True
        return False

    def size(self, pos):
        return -self.par[self.root(pos)]

def check(x):
    UF = UnionFind(N)
    for i in range(N):
        for j in range(i+1,N):
            d = (X[i]-X[j])**2 + (Y[i]-Y[j])**2
            if d <= x:
                UF.unite(i, j)
    return UF.same(0, N-1)

N = int(input())
Z = [list(map(int,input().split())) for _ in range(N)]
X,Y = [list(i) for i in zip(*Z)]
ng = 0
ok = 1<<32
while ok - ng > 1:
    x = (ok+ng) // 2
    if check(x**2):
        ok = x
    else:
        ng = x
ok = (ok + 9) // 10 * 10
print(ok)