program Project1;

{$APPTYPE CONSOLE}
var
f:text;
n,i, k, c:int64;
da:array[1..20000,1..2] of int64;
sd:array[1..20000] of  boolean;
begin
assign(f, 'task.in');
reset(f);
readln(f, n);
FillChar(sd, n, 1);
i:=0;
repeat
  inc(i);
  readln(f, da[i,1], da[i,2]);
until(i=n);
c:=0;
i:=0;
repeat
inc(i);
k:=i;
repeat
inc(k);
  if (da[i, 1]>=da[k,1]) and (da[i,2]>=da[k,2]) and (sd[k]) then begin
  inc(c);
  sd[k]:=False;
  end else
  if (da[i, 1]<=da[k,1]) and (da[i,2]<=da[k,2]) and (sd[i]) then begin
  inc(c);
  sd[i]:=False;
  end else
  if (da[i, 1]<=da[k,2]) and (da[i,2]<=da[k,1]) and (sd[i]) then begin
  inc(c);
  sd[i]:=False;
  end
  else
  if (da[i, 1]>=da[k,2]) and (da[i,2]>=da[k,1]) and (sd[k]) then begin
  sd[k]:=False;
  inc(c);
  end;
until(k=n);
until(i=n-1);
close(f);
assign(f, 'task.out');
rewrite(f);
writeln(f, c);
close(f);

end.