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 Pascal (FPC 2.6.2) (judge verdict: Accepted)

var t:longint;
    a:int64;
    c:char;
begin
  while not eoln do
  begin
    read(c);
    if c='A' then
      inc(t);
    if c='B' then
    begin
      read(c);
      if c='C' then
      begin
        inc(a,t);
        continue;
      end
      else
        if c='A' then
          t:=1
        else
          t:=0;
    end;
    if c='C' then
      t:=0;
  end;
  writeln(a);
end.