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

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int N, ans, mx = -1;
    cin >> N;
    ans = N;
    vector<pair<int,int>> a(N);
    for(auto &&[r, R] : a){
        cin >> r >> R;
        swap(r, R);
    }
    sort(a.begin(), a.end());
    for(auto [R, r] : a){
        if (mx <= r){
            mx = R;
            ans--;
        }
    }
    cout << ans << '\n';
}