MATLAB: Specify two matrix in same time

cell arraysmatlab codermatrixmatrix array

Hi every one
i have this problem if you can help me with
for example :
A=5; AA=[1 2 3;4 5 6;7 8 9];
B=7; BB=[11 12 13; 14 15 16; 17 18 19];
C=12; CC=[21 22 23;24 25 26;27 28 29];
how can i find the maximum number between (A,B,C) witch is (12) and the code show me the second matrix of it directly which is (CC).
thank you