3
A
B
C
18
0 A B
0 A C
0 A B
5 A
1 A B
1 A B
5 B
2 A B Hello World!
2 C B Hello, I'm C.
3 B
4 B
0 A B
1 A B
2 B A Hello A!
2 A B Hello B!
3 B
4 B
5 B