You are given a deck of playing cards. Each card is represented as a string where the first part is its rank (a positive integer, e.g., 1, 2, 3, ...) and the second part is its color: Red (R), Blue (B), Green (G), or Yellow (Y). For example, "10R" represents rank 10, color Red.

A valid set is a collection of cards satisfying exactly one of the following criteria: ...