#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main()
{
	int n;
	cin >> n;

	vector<int> begin(n);
	vector<int> end(n);
	vector<int> minus(n, 0);

	for (int i = 0; i < n; i++)
	{
		int temp1 = 0, temp2 = 0;
		cin >> temp1 >> temp2;
		begin[i] = temp1;
		end[i] = temp2;
	}

	sort(begin.begin(), begin.end());
	sort(end.begin(), end.end());

	int days = 0, temp2 = 0;

	for (int i = 0; i < n; i++)
	{
		auto temp1 = find(end.begin(), end.end(), begin[i]);
		if (temp1 != end.end())
		{
			*temp1 = 0;
			begin[i] = 0;
		}
		else
		{
			days++;
		}
	}

	cout << days;
}