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: Time Limit Exceeded)

program main
implicit none
integer :: i, j, k, l, m
character :: s*200000


read(*,*) s
l = len_trim(s)
if( l.le.2 ) then
   write(*,'(i0)') 0
   stop
end if
k = 0
do 
   j = 0
   m = 1
   do i = m, l-2
      if( s(i:i+2) == 'ABC' ) then
         k = k + 1
         j = 1
         s(i:i+2) ='BCA'
         m = i+3
      end if
   end do
   if( j == 0 ) then
      write(*,'(i0)') k
      stop
   end if
end do

end program main