#include <bits/stdc++.h>

using namespace std;

#define rep(i, a, b) for (int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()

typedef long long ll;

const int MAX_N = 1e6 + 2;

struct interval {
    int a, b;
    bool operator<(const interval& p1) { return b < p1.b; }
} itvs[MAX_N];

int main() {
    cin.tie(0)->sync_with_stdio(false);
    cin.exceptions(cin.failbit);

    int n;
    cin >> n;
    for (int i = 0; i < n; i++) cin >> itvs[i].a >> itvs[i].b;
    sort(itvs, itvs + n);
    int pos = 0;
    int k = 0;
    for (int i = 0; i < n; i++) {
        if (itvs[i].a > pos) {
            pos = itvs[i].b;
            k++;
        }
    }
    cout << k << endl;
    return 0;
}