#pragma GCC optimize(3, "Ofast", "inline")
#include <bits/stdc++.h>
#define int long long
#define x first
#define y second
#define debug(x) cerr << #x " = " << x << '\n';
using namespace std;

void solve() {
    int n;
    cin >> n;
    using pii = pair<int, int>;
    vector<pii> a(n);
    for (int i = 0; i < n; i++) cin >> a[i].x >> a[i].y;
    sort(a.begin(), a.end(), [](pii A, pii B) { return A.y < B.y; });
    int cnt = 1, idx = a.front().y;
    for (int i = 1; i < n; i++) {
        if (a[i].x > idx)
            idx = a[i].y, cnt++;
    }
    cout << cnt << '\n';
}

signed main() {
    // freopen("Sample.in", "r", stdin);
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int T = 1;
    // cin >> T;
    while (T--) solve();
    return 0;
}