You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: cs_nd.m
    path of file: ./repos/SuiteSparse/CSparse/MATLAB/CSparse
    
    the code of the file until where you have to start completion: function p = cs_nd (A)
%CS_ND generalized nested dissection ordering.
%   p = cs_nd(A) computes the nested dissection ordering of a matrix.  Small
%   submatrices (order 500 or less) are ordered via cs_amd.  A must be sparse
%   and symmetric (use p = cs_nd(A|A') if it is not symmetric).
%
%   Example:
%       A = delsq (numgrid ('L', 300)) ;    % matrix used in 'bench'
%       p = cs_nd (A) ;
%       cspy (A (p,p)) ;
%
%   See also CS_AMD, CS_SEP, CS_ESEP, CS_NSEP, AMD.

% CSparse, Copyright (c) 2006-2022, Timothy A. Davis. All Rights Reserved.
% SPDX-License-Identifier: LGPL-2.1+

n = size (A,1) ;
if (n == 1)
    p = 1 ;
elseif (n < 500)
    p = cs_amd (A) ;                % use cs_amd on small graphs

    
function p = cs_nd (A)
%CS_ND generalized nested dissection ordering.
%   p = cs_nd(A) computes the nested dissection ordering of a matrix.  Small
%   submatrices (order 500 or less) are ordered via cs_amd.  A must be sparse
%   and symmetric (use p = cs_nd(A|A') if it is not symmetric).
%
%   Example:
%       A = delsq (numgrid ('L', 300)) ;    % matrix used in 'bench'
%       p = cs_nd (A) ;
%       cspy (A (p,p)) ;
%
%   See also CS_AMD, CS_SEP, CS_ESEP, CS_NSEP, AMD.

% CSparse, Copyright (c) 2006-2022, Timothy A. Davis. All Rights Reserved.
% SPDX-License-Identifier: LGPL-2.1+

n = size (A,1) ;
if (n == 1)
    p = 1 ;
elseif (n < 500)
    p = cs_amd (A) ;                % use cs_amd on small graphs
else
    [s a b] = cs_nsep (A) ;         % find a node separator
    a = a (cs_nd (A (a,a))) ;       % order A(a,a) recursively
    b = b (cs_nd (A (b,b))) ;       % order A(b,b) recursively
    p = [a b s] ;                   % concatenate to obtain the final ordering
end