program flip;
var n,m,i,j,k,s,t,smax:longint;
    a:array[1..16,1..16]of longint;
begin
 assign(input,'flip.in');
 reset(input);
 readln(n,m);
 for i:=1 to n do
  for j:=1 to m do read(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;
  assign(output,'flip.out');rewrite(output);
  writeln(smax);
end.