ps = [tuple(map(lambda s_: int(s_) * 4, input().split())) for _ in range(3)]


def dist(i, t):
    x1, y1 = ps[i]
    x2, y2 = t
    return abs(x1 - x2) + abs(y1 - y2)


def ok(x, y):
    return len({dist(i, (x, y)) for i in range(3)}) == 1


ans = [(x, y) for x in range(-100, 500) for y in range(-100, 500) if ok(x, y)]
if len(ans) > 10:
    print(-1)
else:
    print(len(ans))
    ans.sort()
    for x, y in ans:
        print(x / 4, y / 4)