program bly(input,output);
var
  f:array[1..10000,1..2] of longint;
  p:array[1..10000] of boolean;
  n,ans,z:longint;
  p1,p2:boolean;
  i,j:integer;
  f1,f2:text;
begin
  assign(f1,'punch.in');
  reset(f1);
  readln(f1,n);
  for i:=1 to n do readln(f1,f[i,1],f[i,2]);
  for i:=1 to n do begin
    p1:=false; p2:=false;
    for j:=i+1 to n do begin
      if f[j,1]<=f[i,1] then p1:=true;
      if f[j,2]>=f[i,2] then p2:=true;
      if f[j,1]>f[i,2] then begin p1:=false; p2:=false; end;
      if (p1=true)and(p2=true) then break;
    end;
    if not((p1=true)and(p2=true)) then inc(ans);
  end;
  assign(f2,'punch.out');
  rewrite(f2);
  writeln(f2,ans);
  close(f2);
end.