var m,n,i,j,k,ck,suma,sumal,max,t:longint;
    ca,a:array[1..16,1..16]of longint;
    f:array[1..16] of byte;
begin
assign(input,'flip.in');reset(input);
assign(output,'flip.out');rewrite(output);
readln(n,m);
for i:=1 to n do begin
  for j:=1 to m do read(a[i,j]);
  readln;
end;
t:=1 shl m;  max:=0;
for k:=0 to t-1 do begin
  ck:=k;
  for i:=1 to m do begin f[i]:=ck mod 2;ck:=ck div 2;end;
  ca:=a;
  for i:=1 to n do
    for j:=1 to m do
      if f[i]=0 then ca[i,j]:=-ca[i,j];
  suma:=0;
  for i:=1 to n do begin
    sumal:=0;
    for j:=1 to m do sumal:=sumal+ca[i,j];
    suma:=suma+abs(sumal);
  end;
  if suma>max then max:=suma;
end;
write(max);
close(input);close(output);
end.