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

def distance(x1, y1, x2, y2):
    return ((x2-x1)**2 + (y2-y1)**2) ** 0.5

x, y, z, w = 0, 0, 0, 0
for X, Y in XY:
    x += X
    y += Y
for Z, W in ZW:
    z += Z
    w += W
x /= N
y /= N
z /= N
w /= N

dist1 = 0
dist2 = 0
for X, Y in XY:
    dist1 = max(dist1, distance(x, y, X, Y))
for Z, W in ZW:
    dist2 = max(dist2, distance(z, w, Z, W))

print(dist2/dist1)