#include <bits/stdc++.h>
using namespace std;
int n;
const int N = 1e5+10;
typedef pair<int,int> PII;
PII a[N];
bool compare(const PII&a,const PII&b)
{
    return a.first<b.first;
}
int main()
{
    ios::sync_with_stdio(false);
    cin >> n;
    for(int i = 0;i<n;i++) cin >> a[i].first >> a[i].second;
    sort(a,a+n,compare);
    int cnt = 1;
    int ed = a[0].second;
    for(int i = 1;i<n;i++)
    {
        if(ed>=a[i].first) ed =min(ed,a[i].second);
        else 
        {
            cnt++;
            ed = a[i].second;
        } 
    }
    cout << cnt << endl;
    return 0;
}