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