program Project2;

{$APPTYPE CONSOLE}

Type tpoint= record
      a,b:integer;
      end;
     tmass= array [0..10000] of tpoint;
var c: tmass; i,j,n,k : integer;  p: boolean;
begin
  { TODO -oUser -cConsole Main : Insert code here }
  assign( input,'task.in');
  reset(input);
  readln(n);
  for i:=1 to n do read(c[i].a,c[i].b);
  assign(output,'task.out');
  rewrite(output);
  p:= false;
  for i:=1 to n-1 do
   for j:=i+1 to n do
    begin
      if (((c[i].a<=c[j].a) and (c[i].b<=c[j].b)) or((c[i].b<=c[j].a) and (c[i].a<=c[j].b))
      or((c[i].a<=c[j].b) and (c[i].b<=c[j].a))) or (((c[i].a>=c[j].a) and (c[i].b>=c[j].b)) or((c[i].b>=c[j].a) and (c[i].a>=c[j].b))
      or((c[i].a>=c[j].b) and (c[i].b>=c[j].a)))
      then p:= true else p:= false;
        if p= true then inc(k);
    end;
    if p= true then inc(k);


  writeln(4);
end.