ps = [tuple(map(lambda s_: int(s_) * 8, input().split())) for _ in range(3)]


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


def ok(x, y):
    return dist(0, x, y) == dist(1, x, y) == dist(2, x, y)


sl, sr = -800, 2000
ans = [(x, y) for x in range(sl, sr) for y in range(sl, sr) if ok(x, y)]
if len(ans) > 10:
    print(-1)
else:
    print(len(ans))
    ans.sort()
    for x, y in ans:
        print(x / 8, y / 8)