#include <stdio.h>
#include <algorithm>
using namespace std;
struct map {
    long long int no, go, ID;
} a[1000005], b[1000005];
bool s[1000005];
long long int n, ans, p = -1, h;
bool cmp(map a, map b) { return a.go < b.go; }
bool cmp1(map c, map d) { return c.no < d.no; }
int main() {
    scanf("%lld", &n);
    for (int i = 1; i <= n; ++i) {
        a[i].ID = i;
        b[i].ID = i;
        scanf("%lld%lld", &a[i].no, &a[i].go);
        b[i].no = a[i].no;
        b[i].go = a[i].go;
    }
    sort(a + 1, a + n + 1, cmp);
    sort(b + 1, b + n + 1, cmp1);
    for (int i = 1; i <= n; ++i) {
        if (s[a[i].ID] == 0) {
            p = a[i].go;
            ++ans;
            for (int j = 1; j <= n; j++) {
                if (b[j].no <= p)
                    s[b[j].ID] = 1;
            }
        }
    }
    printf("%lld", ans);
    return 0;
}