P6461 [COCI 2006/2007 #5] TRIK
Description
There are three upside-down cups, and there is a ball under the leftmost cup at the beginning.
Next, a series of swap operations is performed on these three cups. The operations are given by a string, where `A`, `B`, and `C` correspond to the three swap methods shown in the figure above.
You need to find which cup the ball ends up under.
Input Format
One line containing a string representing the sequence of operations. It is guaranteed that the number of operations does not exceed $50$, and each character is one of `A`, `B`, `C`, with no spaces.
Output Format
Output one line with one integer:
- If the ball is under the left cup, output $1$.
- If the ball is under the middle cup, output $2$.
- If the ball is under the right cup, output $3$.
Explanation/Hint
#### Notes
**Translated from [COCI2006-2007](https://hsin.hr/coci/archive/2006_2007/) [CONTEST #5](https://hsin.hr/coci/archive/2006_2007/contest5_tasks.pdf) *T1 TRIK***。
Translated by ChatGPT 5