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');
assign(g,'flip.out');
reset(f);
rewrite(g);
readln(f,n,m);
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.