program filip;
var f,g:text;
    a:array[1..16,1..16] of longint;
    s,ss,smax:longint;
    k,i,j,n,m:byte;
    x:array[0..16] of byte;
begin
     assign(f,'flip.in');
     assign(g,'flip.out');
     reset(f);
     rewrite(g);
     read (f,n,m);
     for i:=1 to n do begin
         for j:=1 to m do
             read (f,a[i,j]);
             readln(f);
     end;
     k:=1;
     for i:=1 to n do x[i]:=0;
         while k>0 do begin
               if x[k]<2 then x[k]:=x[k]+1;
               if k=n then
               begin
                  ss:=0;
                  for j:=1 to m do begin
                  s:=0;
                  for i:=1 to n do begin
                      if x[i]=2 then s:=s-a[i,j] else
                         s:=s+a[i,j];
               end;
     if s<0 then ss:=ss-s else
     ss:=ss+s;
    end;
    if ss>smax then smax:=ss;
    while x[k]=2 do begin k:=k-1; end;
   end else begin k:=k+1; x[k]:=0; end;
  end;
  write(g,smax);
  close(f);
  close(g);
end.