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.