program flip;
var f,g:text;
    n,m,i,j,k,suma,fin,s,ps:longint;
    a:array[1..16,1..16] of longint;

begin
 assign (f,'flip.in'); reset (f);
 assign (g,'flip.out'); rewrite (g);
 readln(f,n,m);
 fillchar(a,sizeof(a),0);
 for i:=1 to n do
  for j:=1 to m do
   read (f,a[i,j]);
  fin:=1 shl m;
  suma:=0;
  for k:=1 to fin do
  begin
   s:=0;
   for i:=1 to n do
   begin
    ps:=0;
    for j:=1 to m do
    begin
     if k and (1 shl j)>0 then
     begin
      ps:=ps-a[i,j];
     end
     else
     begin
      ps:=ps+a[i,j];
     end;
    end;
    if ps<0 then
     s:=s-ps
    else
     s:=s+ps;
   end;
   if s>suma then
    suma:=s;
  end;
  write (g,suma);
  close (F); close (g);
end.