#include <iostream>
#include <algorithm>
#include <cstdio>
using namespace std;

struct node {
    int left;
    int right;
};

const int Max = 1e6 + 5;
node Re[Max];
int n;
int res = 0;

bool cmp(node n1, node n2) {
    if (n1.right != n2.right) {
        return n1.right < n2.right;
    } else {
        return n1.left < n2.left;
    }
}

int main() {
    scanf("%d", &n);
    for (int i = 1; i <= n; i++) {
        scanf("%d%d", &Re[i].left, &Re[i].right);
    }

    sort(Re + 1, Re + n + 1, cmp);

    bool flag = false;
    int k = 0;
    for (int i = 1; i <= n; i++) {
        if (flag == false) {
            res++;
            k = Re[i].right;
            flag = true;
            continue;
        } else {
            if (k >= Re[i].left && k <= Re[i].right) {
                continue;
            } else {
                flag = false;
                i = i - 1;
                continue;
            }
        }
    }

    printf("%d", res);
    return 0;
}