var n,m,i,j,k,ci,max:longint;
    v,aux:array [1..17,1..17] of longint;
    c,c2:array [1..16] of integer;
begin
 assign(input,'flip.in'); reset(input);
 assign(output,'flip.out'); rewrite(output);
  readln(n,m);
  for i:=1 to n do
   for j:=1 to m do read(v[i,j]);
  aux:=v;
  for i:=0 to 1shl(m-1)-1 do begin
   ci:=i;
   for j:=1 to m do begin
    c[j]:=ci mod 2; ci:=ci div 2;
   end;
   for j:=1 to n do
    for k:=1 to m do
     if c[k]=1 then v[j,17]:=v[j,17]+(v[j,k]*-1)
               else v[j,17]:=v[j,17]+v[j,k];
   for j:=1 to n do v[17,17]:=v[17,17]+abs(v[j,17]);
   if max<v[17,17] then max:=v[17,17];
   v:=aux; c:=c2;
  end;
  writeln(max);
 close(input); close(output);
end.