s
3
t
3
s
2
t
2
s
2
t
2
s
1
(6, 5, 5)
(1, −2, 4)
(6, 1, 3)
(4, 1, 4)
t
1
(4, 2, 3)
(3, 1, 4)
(3, 6, 7)
(1, 0, 5)