n = int(input()) r0 = r1 = float("INF") for i in range(n): x, y = map(float, input().split()) if (x, y) == (0, 0): continue r0 = min(r0, x**2+y**2) for i in range(n): x, y = map(float, input().split()) if (x, y) == (0, 0): continue r1 = min(r1, x**2+y**2) print((r1/r0)**(1/2))