var f,g:text;
    a:array[1..16,1..16] of integer;
    n,m,i,j:1..16;
    s,s1,s2:int64;
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]);
   s1:=0; s2:=0;
   for j:=1 to m do
       begin
          s1:=s1+a[i,j];
          s2:=s2-a[i,j];
        end;
   if s1>s2 then s:=s+s1
            else s:=s+s2;
 end;
write(g,s);
close(f); close(g);
end.