#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

typedef pair<long long, long long> Interval;

int merge( vector<Interval>&  intervals){
    if(intervals.size() <= 1){
        return intervals.size();
    }
    sort(intervals.begin(), intervals.end());
    int ans = 1;
    long long right = intervals[0].second;
    for(int i=1; i<intervals.size(); i++){
        auto& interval = intervals[i];
        if(right >= interval.first){
            right = max(right, interval.second);
            continue;
        }
        ans++;
        right = interval.second;
    }
    return ans;
}


int main(){
    int n;
    cin >> n;
    vector<Interval> intervals;
    intervals.reserve(n);
    for(int i=0; i<n; i++){
        long long a, b;
        cin >> a >> b;
        intervals.push_back(make_pair(a, b));
    }
    cout << merge(intervals) << endl;
    return 0;
}