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.