KSA String 2

The KSAAC staff all love KSA, so they like strings that satisfy the following condition.

Let the length of the string be $N$. For every $1 \leq i \leq N$:

• If the remainder of $i$ divided by $3$ is $1$, the $i$-th character is K.
• If the remainder of $i$ divided by $3$ is $2$, the $i$-th character is S.
• If the remainder of $i$ divided by $3$ is $0$, the $i$-th character is A.

The empty string is also a string that the KSAAC staff like.

You may perform the following operations $0$ or more times. Each time, you choose one of the two options below.

• Remove any one existing character.
• Move any one existing character to the front.

Perform appropriate operations on the given string $X$ to turn $X$ into a liked string of the maximum possible length. Find the minimum number of operations required.

The first line contains the string $X$.

Print the minimum number of operations needed to turn the string $X$ into a liked string of the maximum possible length.

• $1 \le |X| \le 5 \times 10^5$
• $X_i \in \{\texttt{K}, \texttt{S}, \texttt{A}\}$