special-subsequences-ag-2

Q4. Special Subsequences "AG" - 2

Problem Description

You have given a string A having Uppercase English letters.

You have to find the number of pairs (i, j) such that A[i] = 'A', A[j] = 'G' and i < j.

Problem Constraints

1 <= length(A) <= 105

Input Format

First and only argument is a string A.

Output Format

Return an long integer denoting the answer.

Example Input

Input 1:

A = "ABCGAG"

Input 2:

A = "GAB"

Example Output

Output 1:

3

Output 2:

0

Example Explanation

Explanation 1:

Subsequence "AG" is 3 times in given string

Explanation 2:

There is no subsequence "AG" in the given string.