#include <stdio.h>
#include <iostream>
#include <algorithm>
#include <map>
#include <string>
using namespace std;
const int N = 1e6 + 50;
const int MAX = 1e6 + 50;
struct arry {
    int a;
    int b;
} m[N];
int n, i, j, ans = 0, k = 0;
bool comp(arry a, arry b) { return a.a < b.a; }
int main() {
    struct arry *p;
    p = m;

    scanf("%d", &n);
    for (i = 0; i < N; i++) {
        (p + i)->a = (p + i)->b = MAX;
    }
    for (i = 0; i < n; i++) {
        scanf("%d %d", &(p + i)->a, &(p + i)->b);
    }
    sort(p, p + n, comp);
    for (i = 0; i < n;) {
        k = i;
        for (j = i + 1; j < n; j++) {
            if ((p + k)->b < (p + j)->a) {
                i++;
                ans++;
                break;
            } else if ((p + k)->b == (p + j)->a) {
                i++;
                continue;
            } else if ((p + k)->b > (p + j)->a && (p + k)->b <= (p + j)->b) {
                i++;
                continue;
            } else {
                i++;
                break;
            }
        }
        if (j == n) {
            ans++;
            break;
        }
    }
    printf("%d", ans);
    return 0;
}