import sys
# input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################
def add(p, q):
    return p[0] + q[0], p[1] + q[1]
def sub(p, q):
    return p[0] - q[0], p[1] - q[1]

def dot(p, q):
    return p[0] * q[0] + p[1] * q[1]

def mul(p, k):
    return p[0] * k, p[1] * k

def dist(p, q):
    return abs(p[0] - q[0]) + abs(p[1] - q[1])

p = na()
q = na()
r = na()
p = mul(p, 10)
q = mul(q, 10)
r = mul(r, 10)

res = []
for x in range(-100, 1100):
    for y in range(-100, 1100):
        if dist((x, y), p) == dist((x, y), q) == dist((x, y), r):
            # print(x, y, dist((x, y), p), dist((x, y), q), dist((x, y), r))
            res.append((x, y))

# print(res)
# print(len(res))
# print(p, q, r)
if len(res) > 5:
    print(-1)
else:
    print(len(res))
    for i in res:
        i = mul(i, 1 / 10)
        print(*i)