How to partition matrix?

I have four matrices of same order A,B,C,D

I combined them in one as

E=[A B;C D];

Now how can I get back A,B,C,D with the help of E?

Answer 1

[Walter Roberson]

[R,C,~] = size(E);
HR = floor(R/2); HC = floor(C/2);
A = E(1:HR, 1:HC, :);
B = E(1:HR, HC+1:C, :);
C = E(HR+1:R, 1:HC, :);
D = E(HR+1:R, HC+1:C, :);

[Ammy]

Thank you very much.