from bisect import bisect

N = int(input())
XY = [list(map(int, input().split())) for _ in range(N)]
D = [[] for _ in range(N)]

for i in range(N - 1):
    x0, y0 = XY[i]
    for j in range(i + 1, N):
        x1, y1 = XY[j]
        dist = (x0 - x1) ** 2 + (y0 - y1) ** 2
        D[i].append((dist, j))
        D[j].append((dist, i))
for i in range(N):
    D[i].sort()

def check(l):
    Q = [0]
    nv = [0] + [1] * (N - 1)
    while Q:
        x = Q.pop()
        for i in range(bisect(D[x], (l * l,N))):
            _,a = D[x][i]
            if a == N - 1:
                return True
            if nv[a]:
                nv[a] = 0
                Q.append(a)
    return False

lb = 0
ub = 10 ** 9

while ub - lb > 1:
    mid = (ub + lb) // 2
    if check(mid * 10):
        ub = mid
    else:
        lb = mid

print(ub * 10)