X = 14;
Y = 10;
N = 13;

end_points_start_x = [ 3, 3,  2,  1,  3, 4, 3, 7, 5,10, 11, 12, 14];
end_points_start_y = [ 6, 5,  2,  1,  7, 5, 8, 3, 4, 3,  6,  9, 10];
end_points_end_x   = [10, 6, 12, 11, 10, 6, 7, 8, 6, 8, 13, 13, 12];
end_points_end_y   = [ 2, 5,  8,  4,  4, 7, 7, 8, 6, 5, 10,  2,  4];