File Naming Convention Validation

Given a file name string, check if it adheres to the naming convention. The file name must be exactly 6 characters long and must contain exactly one occurrence each of the characters A and a, one occurrence each of B and b, and one occurrence each of C and c. The letters can appear in any order. In other words, if you denote the string by \(S\), the following conditions must hold:

[ |S| = 6, \quad \text{and} \quad \forall (U, L) \in {(A, a), (B, b), (C, c)}: ; \text{count}(U, S)=1 ; \text{and} ; \text{count}(L, S)=1. ]

If these conditions are satisfied, the file name is VALID; otherwise, it is INVALID.

inputFormat

The input consists of a single line containing a string \(S\) that represents the file name.

outputFormat

Output a single line: VALID if the file name adheres to the convention, otherwise INVALID.

AaBbCc

VALID