#include<iostream>
#include<algorithm>
using namespace std;
const int N = 100010;
struct Node
{
    int l;
    int r;
}a[N];
bool cmp(Node a, Node b)
{
    return a.r < b.r;
}
int main()
{
    int n;
    cin >> n;
    for (int i = 1; i <= n; ++ i)
    {
        int l, r;
        cin >> l >> r;
        a[i].l = l, a[i].r = r;
    }
    sort(a + 1, a + n + 1, cmp);
    int end = -2e9, res = 0;
    for (int i = 1; i <= n; ++ i)
    {
        if (a[i].l > end)
        {
            res++;
            end = a[i].r;
        }
    }
    cout << res << endl;
    return 0;
}