program suma;  
 const fin = 'flip.in';  
        fout = 'flip.out';  
type matrice = array [1..16,1..16] of longint;  
  type stiva = array [1..16] of longint;  
  var i,j,k,n,m:byte;  
        a:array [1..16,1..16] of longint;  
      s:longint;  
      st,rez:stiva;  
 procedure init;  
 begin  
   st[k]:=3;  
 end;  
 
 function exista:boolean;  
 begin  
 exista:=false;  
  if (k<=n) and (st[k]>-1) then  
  begin  
  dec(st[k],2);  
  exista:=true;  
  end;  
  end;  
  
  function solutie:boolean;  
  begin  
  solutie:=k=n;  
  end;  
  
  procedure prelucrare(b:matrice);  
  var t:longint;  
  begin  
  fillchar(rez,sizeof(rez),0);  
  t:=0;  
  for i:=1 to k do  
  begin  
  for j:=1 to m do  
  begin  
  b[i,j]:=b[i,j]*st[i];  
  inc(rez[j],b[i,j]);  
  end;  
  end;  
  for i:=1 to m do  
  inc(t,abs(rez[i]));  
  if t>s then  
  s:=t;  
  end;  
  
  procedure back;  
  begin  
  k:=1;  
  init;  
  while k>0 do  
  if exista then  
  begin  
  if solutie then  
  prelucrare(a)  
  else  
  begin  
  inc(k);  
  init;  
  end;  
  end  
  else  
  dec(k);  
  end;  
  
  begin  
  {citire}  
  assign(input,fin);  
  assign(output,fout);  
  reset(input);  
  s:=0;  
  read(n,m);  
  for i:=1 to n do  
  for j:=1 to m do  
  read(a[i,j]);  
  back;  
  {tipar}  
  rewrite(output);  
  write(s);  
  close(input);  
  close(output);  
 end.