program ia002;

var
	fIn,fOut:text;
	a:array[1..30,1..30] of longint;
	flip:array[1..30] of longint;
	i,j,n,m,max:longint;

procedure sum;
	var
		i,j,s,r:longint;
	begin
		i:=0; j:=0; s:=0; r:=0;
		for i:=1 to n do begin
			s:=0;
			for j:=1 to m do
				s:=s+a[i,j]*flip[j];
			r:=r+abs(s); end;
		
		if (r>max) then
			max:=r;
	end;

procedure bkt(p:longint);
	begin
		if (p=m+1) then
			sum
		else begin
			flip[p]:=1;
			bkt(p+1);
			flip[p]:=-1;
			bkt(p+1);
		end;
	end;

begin
	assign(fIn,'flip.in');
	assign(fOut,'flip.out'); 
	reset(fIn); rewrite(fOut);

	readln(fIn,n,m);
	for i:=1 to n do begin
		for j:=1 to m do begin
			read(fIn,a[i,j]);
			max:=max+a[i,j]; end;
		readln(fIn); end;
	
	bkt(1);

	writeln(fOut,max);

	close(fIn); close(fOut);
end.