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 Fortran (gfortran v4.8.4) (judge verdict: Runtime Error)

program kadai
implicit none
integer  ::  i,nag,num,flag,j
character(len=200000)  ::  s

read(*,*) s
nag=len(s)
num=0

do i=1,nag-2
    if (s(i:i)=="A") then
        flag=0
        j=i
        do while(flag==0)
            j=j+1
            if (s(j:j+1)=="BB" .or. s(j:j+1)=="CC" .or. s(j:j+1)=="CB") then
                flag=1
            end if
            if (s(j:j+1)=="BC") then
                num=num+1
                j=j+1
            end if
        end do
    end if
end do

write(*,*) num

end program kadai