#include <iostream>

#include <algorithm>

#include <queue>

using namespace std;

typedef long long ll;

void solve(){

int N; cin >> N;

pair<int,int> arr[N];

for (int i = 0; i < N; i++) {

cin >> arr[i].first >> arr[i].second;

}

sort(arr, arr+N);

priority_queue<int> pq; pq.push(-arr[0].second);

for (int i = 1; i < N; i++){

auto [a,b] = arr[i];

if (a >= -pq.top()) pq.pop();

pq.push(-b);

}

cout << pq.size();

}

int main()

{

cin.tie(0)->sync_with_stdio(0);

solve();

return 0;

}