function r = card_rank ( n )

%*****************************************************************************80
%
%% card_rank() is given the index of a card and returns its rank.
%
%  Discussion:
%
%    index:  1  2  3  4  5  6  7  8  9 10 11 12 13
%           14 15 16 17 19 19 20 21 22 23 24 25 26
%           27 28 29 30 31 32 33 34 35 36 37 38 39
%           40 41 42 43 44 45 46 47 48 49 50 51 52
%           --------------------------------------
%    rank:   1  2  3  4  5  6  7  8  9 10 11 12 13
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    15 April 2022
%
%  Author:
%
%    John Burkardt
%
%  Input:
%
%    integer N: the index of the card.  1 <= index <= 52.
%
%  Output:
%
%    integer R: the rank of the card.  1 <= r <= 13.
%
  r = mod ( abs ( n ) - 1, 13 ) + 1;

  return
end

