#include <bits/stdc++.h>
#define INL inline
#define REG register
#define DB double
#define LDB long double
#define ULL unsigned long long
#define LL long long

#define RPT(i, x, y) for (REG int i = (x); i < (y); i++)
#define DRPT(i, x, y) for (REG int i = (x); i > (y); i--)
#define MST(a, b) memset((a), (b), sizeof(a))
#define MRK() cout << "Mark" << endl;
#define WRT(x) cout << #x << " = " << (x) << endl;

#define MAXN 1010000
#define MAXM 10000
#define MOD 998244353
#define INF 0x3f3f3f3f
#define LLINF 0x3f3f3f3f3f3f3f3f
#define EPS 1e-5

#define _ 0
using namespace std;

struct p {
    int l, r;
} pir[MAXN];

bool cmp(p p1, p p2) { return p1.r < p2.r; }

int n;
int main() {
    cin >> n;
    RPT(i, 0, n)
    cin >> pir[i].l >> pir[i].r;
    sort(pir, pir + n, cmp);
    int pos = -INF;
    int ans = 0;
    RPT(i, 0, n) {
        if (pir[i].l > pos) {
            ans++;
            pos = pir[i].r;
        }
    }
    cout << ans;

    // cout<<pir[i].l<<' '<<pir[i].r<<endl;
    return ~~(0 ^ _ ^ 0);
}