#include <iostream>
#include <algorithm>
using namespace std;
const int N = 1e5 + 10;

struct node
{
    int l, r;

    bool operator < (const node &W) const
    {
        return r < W.r;
    }
    
} arr[N];

int main()
{
    int n;
    cin >> n;
    for (int i = 1; i <= n; i++) 
        cin >> arr[i].l >> arr[i].r;
    
    //按右端点从小到大排序
    sort(arr + 1, arr + 1 + n);
    
    int ans = 0;
    int R = -2e9; //R表示上一连续区间的最右端的点
    for (int i = 1; i <= n; i++)
    {
        if (arr[i].l > R) //如果不能覆盖掉右端点，则点数+1，更新右端点
        {
            ans++;
            R = arr[i].r;
        }
    }
    
    cout << ans << endl;
    
    return 0;
}