# haru: pypy
import sys
input = sys.stdin.readline
II = lambda : int(input())
MI = lambda : map(int, input().split())
LI = lambda : [int(a) for a in input().split()]
SI = lambda : input().rstrip()
LLI = lambda n : [[int(a) for a in input().split()] for _ in range(n)]
LSI = lambda n : [input().rstrip() for _ in range(n)]
MI_1 = lambda : map(lambda x:int(x)-1, input().split())
LI_1 = lambda : [int(a)-1 for a in input().split()]

mod = 998244353
inf = 1001001001001001001
ordalp = lambda s : ord(s)-65 if s.isupper() else ord(s)-97
ordallalp = lambda s : ord(s)-39 if s.isupper() else ord(s)-97
yes = lambda : print("Yes")
no = lambda : print("No")
yn = lambda flag : print("Yes" if flag else "No")

prinf = lambda ans : print(ans if ans < 1000001001001001001 else -1)
alplow = "abcdefghijklmnopqrstuvwxyz"
alpup = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
alpall = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
URDL = {'U':(-1,0), 'R':(0,1), 'D':(1,0), 'L':(0,-1)}
DIR_4 = [[-1,0],[0,1],[1,0],[0,-1]]
DIR_8 = [[-1,0],[-1,1],[0,1],[1,1],[1,0],[1,-1],[0,-1],[-1,-1]]
DIR_BISHOP = [[-1,1],[1,1],[1,-1],[-1,-1]]
prime60 = [2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59]
sys.set_int_max_str_digits(0)
# sys.setrecursionlimit(10**6)
# import pypyjit
# pypyjit.set_param('max_unroll_recursion=-1')

from collections import defaultdict,deque
from heapq import heappop,heappush
from bisect import bisect_left,bisect_right
DD = defaultdict
BSL = bisect_left
BSR = bisect_right

ps = [tuple(map(int, input().split())) for _ in range(3)]

ps = [(x + y, x - y) for x, y in ps]

l = min(x for x, y in ps)
r = max(x for x, y in ps)
d = min(y for x, y in ps)
u = max(y for x, y in ps)

w = r - l
h = u - d

for a in (l, r):
    for b in (d, u):
        if all(x == a or y == b for x, y in ps):
            print(-1)
            exit()

if w > h and all(x in (l, r) for x, y in ps):
    print(-1)
    exit()

if h > w and all(y in (d, u) for x, y in ps):
    print(-1)
    exit()

m = max(w, h)

if w > h:
    a = l + r
    for x, y in ps:
        if l < x < r:
            b = y
            break

    ch = [(a, 2 * b - m), (a, 2 * b + m)]
elif h > w:
    b = d + u

    for x, y in ps:
        if d < y < u:
            a = x
            break

    ch = [(2 * a - m, b), (2 * a + m, b)]
else:
    ch = [(l + r, d + u)]

ans = set()

for a, b in ch:
    ok = 1
    for x, y in ps:
        d = max(abs(a - 2 * x), abs(b - 2 * y))
        if d != m:
            ok = 0
    if ok:
        ans.add((a + b, a - b))

ans = sorted(ans)
print(len(ans))
for x, y in ans:
    print(x / 4, y / 4)