Problem:
Score : 600 points

Problem Statement

You are given a string s consisting of A, B and C.

Snuke wants to perform the following operation on s as many times as possible:

Choose a contiguous substring of s that reads ABC and replace it with BCA.

Find the maximum possible number of operations.

Constraints

1 \leq |s| \leq 200000

Each character of s is A, B and C.

Input

Input is given from Standard Input in the following format:

s

Output

Find the maximum possible number of operations.

Sample Input 1

ABCABC

Sample Output 1

3

You can perform the operations three times as follows: ABCABC → BCAABC → BCABCA → BCBCAA. This is the maximum result.

Sample Input 2

C

Sample Output 2

0

Sample Input 3

ABCACCBABCBCAABCB

Sample Output 3

6

Solution in Python (3.4.3) (judge verdict: Time Limit Exceeded)

s=input()


i=0
c=0
flag=0
while True:
	if i>len(s)-3: break
	if s[i]=="A" and s[i+1]=="B" and s[i+2]=="C":
		s=s[:i]+"B"+s[i+1:]
		s=s[:i+1]+"C"+s[i+2:]
		s=s[:i+2]+"A"+s[i+3:]
		c+=1
		if i>0:
			i-=1
			flag+=1
		continue
	else:
		if flag:
			i+=2+flag
			flag=0
		else: i+=1

print(c)