var m,n,i,j,k,ck,suma,suml,max,t:longint;     
    v,cv:array[0..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(v[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; v[0,i]:=0;end;     
    cv:=v;     
    for i:=1 to n do     
      for j:=1 to m do     
        if f[j]=0 then cv[i,j]:=-cv[i,j];     
    suma:=0;     
    for i:=1 to n do begin     
      suml:=0;     
      for j:=1 to m do     
        suml:=suml+cv[i,j];     
      suma:=suma+abs(suml);     
    end;     
    if suma>max then max:=suma;     
  end;     
  write(max);     
  close(input); close(output);     
end.