Problem 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 $3$.

AB

3

CBABCACCC

1

Hint

Notes

Translated from COCI2006-2007 CONTEST #5 T1 TRIK。

Translated by ChatGPT 5