Tuple Checking

Input is denoted by a string A

• Your task is to find the number of tuples of 4 distinct indices modulo 10⁹ + 7 (i,j,k,l) such that (A_i,A_j,A_k,A_l) = (A,W,A,B)

Example Case

Input: A = "AWABAB" Output: 12

Case 1-2

Input: The input is too long! Access both case inputs here.

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