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

using namespace std;
using ll = long long;


int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    ll n,m;
    cin>>n>>m;
    swap(n,m);
    vector<ll> l(n),r(n);
    for(int i = 0;i<n;i++) cin>>l[i]>>r[i];
    ll ans = m;
    vector<int> idx(n);
    for(int i = 0;i<n;i++) idx[i] = i;
    sort(idx.begin(),idx.end(),[&](int i,int j){
        if(r[i]!=r[j]) return r[i] < r[j];
        return l[i] < l[j];
    });
    ll prev = -1;
    for(int i = 0;i<n;i++){
        int ni = idx[i];
        if(prev<l[ni]){
            prev = r[ni];
            ans--;
        }
    }
    cout<<ans<<endl;
}