#include <iostream>
#include <algorithm>
#include <cstring>
#include <cstdio>

using namespace std;
typedef long long LL;

const int N = 100010;
struct range{
    int l,r;
}seg[N];
bool cmp(const range &a,const range &b){
    return a.r < b.r;
}
int n;

int main(){
    scanf("%d",&n);
    for(int i = 0;i < n;++i)    scanf("%d%d",&seg[i].l,&seg[i].r);
    sort(seg,seg + n,cmp);
    LL cnt = 0;
    int last = -2e9;
    for(int i = 0;i < n;++i){
        if(last < seg[i].l){
            cnt++;
            last = seg[i].r;
        }
    }
    printf("%lld",cnt);
    return 0;
}