function B=inv_rec(A);
[n m] = size( A );
if n~=m
   error( 'pleaca de la calculator' );   
end

if ( n == 1 )
    B = 1 / A;
else
    disp ( 'numarul ' + n );
    A;
    B = zeros( n );
    B( 1:n/2, 1:n/2 ) = inv_rec( A( 1:n/2, 1:n/2 ) );
    B( n/2+1:n, n/2+1:n ) = inv_rec( A( n/2+1:n, n/2+1:n ) );
    B( n/2+1:n, 1:n/2 ) = - B( n/2+1:n, n/2+1:n ) * A( n/2+1:n, 1:n/2 ) * B( 1:n/2, 1:n/2 );
end