i want to pick n1*2 matrix (sub matrix 1) randomly from m*2 matrix (n1<m). condition is while picking n2*2 (submatrix 2) the rows of submatrix 1 should not be repeated in the subsequent selection. please help me

example:

A = [ 1 2 ; 3 4 ; 5 6 ; 7 8 ; 9 10; 11 12 ];

output should be

A1 = [ 1 2 ; 3 4 ];

A2 = [ 5 6 ; 7 8 ; ];

A3 = [ 9 10 ; 11 12];