class Point:
    def __init__(self, x, y, z):
        self.x = x
        self.y = y
        self.z = z

    def __sub__(self, o):
        return Point(self.x - o.x, self.y - o.y, self.z - o.z)

    def __str__(self):
        return f"({self.x}, {self.y}, {self.z})"

    def cross(self, o):
        x = self.y * o.z - self.z * o.y
        y = self.z * o.x - self.x * o.z
        z = self.x * o.y - self.y * o.x
        return Point(x, y, z)

p0 = Point(1, 1, 0)
p1 = Point(0, 1, 1)
p2 = Point(1, 0, 1)

e1 = p1 - p0
print(e1)

e2 = p2 - p0
print(e2)

n = e1.cross(e2)
print(n)

# Find A, B, C and D
D = -(n.x * p0.x + n.y * p0.y + n.z * p0.z)
print(n.x, n.y, n.z, D)