#include <bits/stdc++.h>
using namespace std;
struct inter {
    int a;
    int b;
    bool operator<(const inter t) const { return this->a < t.a; }
    bool operator>(const inter t) const { return this->a > t.a; }
};
int main() {
    // freopen("in.txt","r",stdin);
    int n = 0;
    cin >> n;
    vector<inter> it(n);
    vector<int> temp(n);
    int i = 0;
    while (i < n) {
        cin >> it[i].a >> it[i].b;
        i++;
    }
    sort(it.begin(), it.end());
    i = 0;
    int right = it[0].b, cnt = 1;
    while (i < n) {
        if (right < it[i].a) {
            right = it[i].b;
            cnt++;
        } else if (right > it[i].b) {
            right = it[i].b;
        }
        i++;
    }
    cout << cnt << endl;
}