function [n] = gauss(m)
  ms = size(m);
  mc = ms(1,2);
  ml = ms(1,1);
  if ml + 1 ~= mc
    error('Matriz invalida.')
  else
    a = 1;
    for a = 1:ml
      k = m(a,a);
      if k == 0
        c = a + 1;
        for c = (a + 1):ml
          if m(c,a) ~= 0
            b = 1;
            k = m(c,a);
            for b = 1:mc
              m(a,b) = m(a,b) - k*m(c,b);
            endfor
            break;
          endif
        endfor
        k = m(a,a);
        if k == 0
          error('Matriz invalida.');
        endif
      endif
      b = 1;
      for b = 1:mc
        m(a,b) = m(a,b)/k;
      endfor
      c = a +1;
      for c = (a+1):ml
        b = 1;
        k = m(c,a);
        for b = 1:mc
          m(c,b) = m(c,b) - k*m(a,b);
        endfor
      endfor
    endfor
  endif
  m
  for a = 1:ml-1
    for c = 1:a
      k = m(ml-a,mc-c);
      for b = 1:mc
        m(ml-a,b)=m(ml-a,b)-k*m(ml+1-c,b);
      endfor
      m
    endfor
  endfor
  for a = 1:ml
    n(a,1) = m(a,mc);
  endfor
endfunction