A = (1, 5)
B = (1, 4)
C = (1, 3)
D = (1, 2)
E = (1, 0)
F = (1, -1)
G = (1, -2)
H = (1, -3)
I = (2, 1)
J = (3, 1)
K = (4, 1)
L = (5, 1)
M = (0, 1)
N = (-1, 1)
O = (-2, 1)
P = (-3, 1)
a = Segment(B, M)
b = Segment(M, I)
c = Segment(I, G)
d = Segment(G, B)