Problem Statement

You are given a string S of length N consisting of A,R,C.
As long as S contains three consecutive characters that are ARC, you can perform the operation below.

• In an odd-numbered (1-st, 3-rd, 5-th, ...) operation, choose in S three consecutive characters that are ARC, and replace them with R.
• In an even-numbered (2-nd, 4-th, 6-th, ...) operation, choose in S three consecutive characters that are ARC, and replace them with AC.

Find the maximum number of operations that can be performed.

Input

Input is given from Standard Input in the following format:
N
S

Output

Print the answer.

Constraints

• $1 \leq N \leq 2\times 10^5$
• S is a string of length N consisting of A,R,C.

Sample Input 1

6
AARCCC

Sample Output 1

2

You can perform two operations as follows.
AARCCC → ARCC → ACC

Sample Input 2

5
AAAAA

Sample Output 2

0

S does not contain three consecutive characters that are ARC, so you cannot perform the operation at all.

Sample Input 3

9
ARCARCARC

Sample Output 3

3

见题面 Input 部分

见题面 Output 部分