1 Q 0 1 2 3
2 A a b
3 s 0
4 F 1 3
5 t a 0 1
6 t b 0 2
7 t a 1 3
8 t b 1 3
9 t a 2 0
10 t b 2 1
11 t a 3 2
12 t b 3 3