#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
vector<pair<int, int> > seq;
inline int mmax(int a, int b) { return a > b ? a : b; }
inline int mmin(int a, int b) { return a < b ? a : b; }
int main() {
    cin.sync_with_stdio(0);
    cin.tie(0);
    int n, l, r;
    cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> l >> r;
        seq.push_back(pair<int, int>(l, r));
    }
    sort(seq.begin(), seq.end());
    /*
    for(int i = 0; i < n; i++) {
            cout << seq[i].first << ' ' << seq[i].second << endl;
    }
    */
    int ans = n;
    for (int i = 0; i < n - 1; i++) {
        if (seq[i].second >= seq[i + 1].first) {
            pair<int, int> tmp =
                pair<int, int>(mmax(seq[i].first, seq[i + 1].first), mmin(seq[i].second, seq[i + 1].second));
            seq[i] = seq[i + 1] = tmp;
            ans--;
        }
    }
    cout << ans << endl;
    return 0;
}