def manhattan_distance(p1, p2):
  x1, y1 = p1
  x2, y2 = p2
  return abs(x1 - x2) + abs(y1 - y2)

def is_circumcenter(c, p, q, r):
  d = manhattan_distance(c, p)
  return d == manhattan_distance(c, q) == manhattan_distance(c, r)

p = tuple(map(int, input().split()))
q = tuple(map(int, input().split()))
r = tuple(map(int, input().split()))

ans = []
for x2 in range(210):
  for y2 in range(210):
    x = x2 / 2
    y = y2 / 2
    if is_circumcenter((x, y), p, q, r):
      ans.append((x, y))

if len(ans) > 1:
  print(-1)
else:
  print(len(ans))
  for v in ans:
    print(*v)