MATLAB: Call all element inside cell (this cell contain another set of cells)

Question

Let's say, I have a cell

cell_A=1×3 cell

cell_A= { cell A1   cell A2  cell A3};
cell_A1=1x2 cell={[1 1 1;2 2 2],[3 3 3;4 4 4;5 5 5]};
cell_A2=1x2 cell={[9 9 9;5 5 5],[7 8 9;6 5 4;5 5 5;8 8 8]};
cell_A2=1x4 cell={[9 8 7;4 5 6;5 5 5;6 6 6],[9 9 9;5 5 5],[1 1 1;2 2 2],[3 2 1;1 2 3;5 5 5;7 7 7]};
cell_A= { {[1 1 1;2 2 2],[3 3 3;4 4 4;5 5 5]}   {[9 9 9;5 5 5],[7 8 9;6 5 4;5 5 5;8 8 8]}  {[9 8 7;4 5 6;5 5 5;6 6 6],[9 9 9;5 5 5],[1 1 1;2 2 2],[3 2 1;1 2 3;5 5 5;7 7 7]}};

How can I call all element from cell A, and generate cell_result (1×8 cell)

cell_result={[1 1 1;2 2 2],[3 3 3;4 4 4;5 5 5],[9 9 9;5 5 5],[7 8 9;6 5 4;5 5 5;8 8 8],[9 8 7;4 5 6;5 5 5;6 6 6],[9 9 9;5 5 5],[1 1 1;2 2 2],[3 2 1;1 2 3;5 5 5;7 7 7]};

Answer 1

[cell_A{:}]