#include <bits/stdc++.h>
using namespace std;

struct Interval {
    int left;
    int right;
    operator<(const Interval &x) {  //用于sort
        return (right < x.right || (right == x.right && left > x.left));
    }
} tot[1000000];

//尽可能往右选的同时保证每个区间都有个点
int choose_point(Interval *x, int n) {
    sort(x, x + n);
    int ans = 1, r = x[0].right;
    for (int i = 1; i < n; i++) {
        if (x[i].left > r) {
            r = x[i].right;
            ans++;
        }
    }
    return ans;
}

int main() {
    int n;
    cin >> n;
    if (n < 1 || n > 1000000)
        return 0;
    for (int i = 0; i < n; i++) {
        cin >> tot[i].left;
        cin >> tot[i].right;
        if (tot[i].left < 1 || tot[i].left > 1000000 || tot[i].right < 1 || tot[i].right > 1000000)
            return 0;
    }
    cout << choose_point(tot, n);
    return 0;
}

/sandbox/1/a.cpp:7:34: error: ISO C++ forbids declaration of 'operator<' with no type [-fpermissive]
     operator < (const Interval &x) { //用于sort
                                  ^