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);
     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;
     close(f);
     assign(g,'flip.out'); rewrite(g);
     writeln(g,smax);
     close(g);
end.