Program Flip;  
 var n,m,i,j,k,ci,max:longint;     
    v,aux:array [1..17,1..17] of longint;     
     c,c2:array [1..16] of integer;     
     f,g:Text;  
 begin    
  assign(f,'flip.in'); reset(f);     
  assign(g,'flip.out'); rewrite(g);     
   readln(f,n,m);     
   for i:=1 to n do    
    for j:=1 to m do read(f,v[i,j]);     
  aux:=v;     
  for i:=0 to 1shl(m-1)-1 do begin    
    ci:=i;     
    for j:=1 to m do begin    
     c[j]:=ci mod 2; ci:=ci div 2;     
    end;     
    //flip si sume in modul     
for j:=1 to n do    
     for k:=1 to m do    
     if c[k]=1 then v[j,17]:=v[j,17]+(v[j,k]*-1)     
                else v[j,17]:=v[j,17]+v[j,k];     
    for j:=1 to n do v[17,17]:=v[17,17]+abs(v[j,17]);     
   if max<v[17,17] then max:=v[17,17];     
    v:=aux; c:=c2;     
   end;     
   writeln(g,max);     
  close(f); close(g);     
 end.