var f,g:text;
    a:array[1..16,1..16] of longint;   
    s,ss,smax:longint;   
    k,i,j,n,m:byte;   
    x:array[0..16] of byte;   
begin  
     assign(f,'flip.in');   
     assign(g,'flip.out');   
     reset(f);   
     rewrite(g);   
     read (f,n,m);   
     for i:=1 to n do begin  
         for j:=1 to m do  
             read (f,a[i,j]);   
             readln(f);   
     end;   
     k:=1;   
     for i:=1 to n do x[i]:=0;   
         while k>0 do begin  
               if x[k]<2 then x[k]:=x[k]+1;   
               if k=n then  
               begin  
                  ss:=0;   
                  for j:=1 to m do begin  
                  s:=0;   
                  for i:=1 to n do begin  
                      if x[i]=2 then s:=s-a[i,j] else  
                         s:=s+a[i,j];   
               end;   
     if s<0 then ss:=ss-s else  
     ss:=ss+s;   
    end;   
    if ss>smax then smax:=ss;   
    while x[k]=2 do begin k:=k-1; end;   
   end else begin k:=k+1; x[k]:=0; end;   
  end;   
  write(g,smax);   
  close(f);   
  close(g);   
end.