#include "bits/stdc++.h"
#define ll               long long

using namespace std;


void SOLVE(){
    int n,l,r;
    cin>>n;
    vector<pair<int,int>>v;
    for(int i=0;i<n;i++){
        cin>>l>>r;
        v.push_back({r,l});
    }

    sort(v.begin(),v.end());


    int cur=0;
    int cnt=0;
    for(int i=0;i<n;i++){
        if(v[i].second>=cur){
            cnt++;
            cur=v[i].first;
        }
    }
    cout<<cnt<<endl;


}

signed main(){
    int T=1;
//    cin>>T;
    while(T--)
        SOLVE();

    return 0;
}