Then, the algorithm $(2 \times Q) \times(4-3)$ can get 24.
Wang Liang, in a game, drew $7,7,7,3$, and found that $7+7+7+3=24$. If a set of 4 cards that can be directly added up to 24 is called a "friendly card set",
then, the number of different "friendly card sets" containing the maximum number 7 is $\qquad$ sets.
【Answer】 4 groups
【Explanation】 They are $7,7,7,3 ; 7,7,6,4 ; 7,7,5,5 ; 7,6,6,5$.