var n,m,i,j,k,s,t,smax:longint;
    a:array[1..16,1..16] of longint;
    f,g:text;
begin
 assign(f,'flip.in'); reset(f);
 assign(g,'flip.out'); rewrite(g);
 read(f,n,m);
 smax:=0;
 for i:=1 to n do
  for j:=1 to m do
   read(f,a[i,j]);
 for i:=0 to (1 shl m)-1 do begin
  s:=0;
  for k:=1 to n do begin
   t:=0;
   for j:=1 to m  do
    if i and (1 shl (j-1))>0 then
     inc(t,-a[k,j])
    else
     inc(t,a[k,j]);
   if t>-t then
    inc(s,t)
   else
    inc(s,-t);
  end;
  if smax<s then
   smax:=s;
 end;
 writeln(g,smax);
 close(f); close(g);
end.