//贪心
#include <iostream>
#include <algorithm>
#include <cstdio>
using namespace std;
typedef pair<int, int> pii;
const int N = 100010;
pii a[N];
bool cmp(pii p, pii q){
    return p.second > q.second;
}
int main(){
    int n;
    cin >> n;
    for(int i = 0; i < n; i ++ ){
        scanf("%d%d", &a[i].first, &a[i].second);
    }
    sort(a, a+n, cmp);
    int cnt = 1;
    int last = a[0].second;
    for(int i = 1; i < n; i ++ ){
        if(a[i].first > last){
            cnt ++ ;
            last = max(last, a[i].second);
        }
    }
    cout << cnt << endl;
    return 0;
}

//区间合并
#include <iostream>
#include <algorithm>
#include <cstdio>
using namespace std;
typedef pair<int, int> pii;
const int N = 100010;
pii a[N];
int main(){
    int n;
    cin >> n;
    for(int i = 0; i < n; i ++ ){
        scanf("%d%d", &a[i].first, &a[i].second);
    }
    sort(a, a+n);
    int cnt = 1;
    int last = a[0].second;
    for(int i = 1; i < n; i ++ ){
        if(a[i].first > last){
            cnt ++ ;
            last = a[i].second;
        }else{
            last = max(last, a[i].second);
        }
    }
    cout << cnt << endl;
    return 0;
}