from collections import deque
def check(x):
    G = [[] for _ in range(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:
                G[i].append(j)
                G[j].append(i)
    flg = [False] * N
    flg[0] = True
    Queue = deque()
    Queue.append(0)
    while Queue:
        pos = Queue.popleft()
        for nxt in G[pos]:
            if flg[nxt]:
                continue
            flg[nxt] = True
            Queue.append(nxt)
    return flg[-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)