#include <fstream>
#include <algorithm>
#define max_size 50009
using namespace std;

ifstream f("int.in"); ofstream g("int.out");

int n, sol = 1;
struct obj
{
    int first;
    int second;
}   v[max_size];

inline bool  cmp(obj a, obj b)
{
    if(a.second < b.second) return 1;
    if(a.second > b.second) return 0;
    if(a.first < b.first) return 1;
    return 0;
}

int main()
{
    f >> n;
    for(int i = 1; i <= n; ++i) f >> v[i].first >> v[i].second;

    sort(v + 1, v + n + 1, cmp);

    //for(int i = 1; i <= n; ++i) g << v[i].first << ' ' << v[i].second << '\n';
    for(int i = 2, j = i - 1; i <= n; ++i)
        if(v[i].first >= v[j].second)
        {
            ++sol;
            j = i;
        }

    g << sol << '\n';
}