#include <iostream>
#include <fstream>
#include <algorithm>

using namespace std;

struct disp{
	int x, y;
};

int N;

disp Disp[16005];

bool cmp(disp s1, disp s2)
{
	return s1.x < s2.x;
}

int main()
{
	ifstream in("granita.in");
	ofstream out("granita.out");
	
	in >> N;
	for(int i = 0; i < N; ++i)
		in >> Disp[i].x >> Disp[i].y;
		
	sort(Disp, Disp + N, cmp);
	int redund = 0;
	
	int i = 0;
	while(i < N)
	{
		int j = i + 1;
		while(j < N)
		{
			if(Disp[j].x > Disp[i].x && Disp[j].y < Disp[i].y)
				++j, ++redund;
			else
				break;
		}
		i = j;
	}
	
	out << redund;
	return 0;
}