class MAIN is

  f(n:INT):INT
    pre n >= 0
  is
    if n = 0 then return 1; end;
    return n - m(f(n-1));
  end;

  m(n:INT):INT
    pre n >= 0
  is
    if n = 0 then return 0; end;
    return n - f(m(n-1));
  end;

  main is
    loop i ::= 0.upto!(19);
      #OUT + #FMT("%2d ", f(i));
    end;
    #OUT + "\n";
    loop i ::= 0.upto!(19);
      #OUT + #FMT("%2d ", m(i));
    end;
  end;
end;