#include<bits/stdc++.h>
#define ll long long
using namespace std;

int main() {
    ll n,k;
    cin>>n>>k;
    vector<pair<ll,ll>>a={{0,0}};
    for (int i=0;i<k;++i){
        ll l,r;
        cin >>l>>r;
        if (l>r) swap(l,r);
        a.push_back({l,r});
    }
    sort(a.begin(),a.end(),[](const pair<ll,ll>& x, const pair<ll,ll>& y) {
        return x.second < y.second;
    });
    int res = 1;
    ll x = a[1].second - 1;
    //meothinhle
    for (ll i = 2; i <= k; ++i){
        if (a[i].first > x){
            x = a[i].second - 1;
            res++;
        }
    }
    cout <<res+1;
    return 0;
}

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
const ll nmax = 1000;

pair<ll, ll> a[nmax + 5];
ll n, k;
bool cmp (pair<ll, ll> x, pair<ll, ll> y)
{
  return x . second < y . second;
}
int main()
{

  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);

  cin >> n >> k;
  for (ll i = 1; i <= k; ++i)
  {
    cin >> a[i] . first >> a[i] . second;
    if (a[i] . first > a[i] . second)
    {
      swap(a[i] . first, a[i] . second);
    }
  }
  sort (a + 1, a + 1 + k, cmp);
  ll ans = 1, p = a[1] . second - 1;
  for (ll i = 2; i <= k; ++i)
  {
    if (a[i] . first > p)
    {
      ans++;
      p = a[i] . second - 1;
    }
  }
  cout << ans + 1;
  return 0;
}