program flip;
type ma=array [1..16,1..16] of longint;
     ta=array [1..16] of -1..1;
var n,m,i,j:longint;
    smax:longint;
    a:ma;
    sol:ta;
    fin,fout:text;
procedure evaluare;
var i,j,s,sc:longint;
begin
   s:=0;
   for i:=1 to m do
       begin
       sc:=a[1,i];
       for j:=2 to n do
           sc:=sc+sol[j]*a[j,i];
           s:=s+abs(sc);
       end;
       if smax<s then smax:=s;
   end;
procedure back(p:integer);
begin
    sol[p]:=1;
    if p=n then
          evaluare
    else
          back(p+1);
    sol[p]:=-1;
    if p=n then
          evaluare
    else
          back(p+1);
end;
begin
     assign(fin,'flip.in');reset(fin);
     assign(fout,'flip.out');rewrite(fout);
     readln(fin,n,m);
     for i:=1 to n do
         begin
         for j:=1 to m do
             read (fin,a[i,j]);
     readln(fin);
     end;
     close(fin);
     smax:=0;
     back(1);
     write(fout,smax);
     close(fout);
end.