#include <iostream>
#include <algorithm>
#include <fstream>
using namespace std;
struct node {
    int left;
    int right;
};
bool cmp(node n1, node n2) {
    if (n1.left != n2.left)
        return n1.left < n2.left;
    else
        return n1.right < n2.right;
}
//在使用之前应该先判断是否会有交集
node Jiao(node n1, node n2) {
    int left = max(n1.left, n2.left);
    int right = min(n1.right, n2.right);
    node n;
    n.left = left;
    n.right = right;
    return n;
}
const int max_size = 1e6;
node a[max_size];
int n;
int main() {
    cin >> n;
    for (int i = 1; i <= n; i++) {
        cin >> a[i - 1].left >> a[i - 1].right;
    }
    sort(a, a + n, cmp);
    node int_sec;  //交集
    int_sec.left = 0;
    int_sec.right = 0;
    int Count = 0;
    for (int i = 0; i < n; i++) {
        //说明会有交集
        if (a[i].left <= int_sec.right) {
            int_sec = Jiao(int_sec, a[i]);
            // cout<<int_sec.left<<" "<<int_sec.right<<endl;
        } else {
            Count++;
            int_sec = a[i];
        }
    }
    cout << Count << endl;
    return 0;
}