#include <bits/stdc++.h>
using namespace std;
 
#define ms(s,n) memset(s,n,sizeof(s))
#define all(a) a.begin(),a.end()
#define present(t, x) (t.find(x) != t.end())
#define sz(a) int((a).size())
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define FORd(i, a, b) for (int i = (a) - 1; i >= (b); --i)
#define pb push_back
#define pf push_front
#define fi first
#define se second
#define mp make_pair
 
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int,int> pi;
typedef vector<int> vi;
typedef vector<pi> vii;
 
const int MOD = (int) 1e9+7;
const int INF = (int) 1e9+1;
inline ll gcd(ll a,ll b){ll r;while(b){r=a%b;a=b;b=r;}return a;}
inline ll lcm(ll a,ll b){return a/gcd(a,b)*b;}
 
bool cmp(pi a, pi b){
    return a.se<b.se;
}
 
int main(){
    int n;cin>>n;
    vii v(n);
    FOR(i,0,n){
        cin>>v[i].fi>>v[i].se;
    }
    sort(all(v),cmp);
    int ans =1;
    int tmp=v[0].se;
    FOR(i,1,n){
        if(v[i].fi>tmp){
            ans++;
            tmp=v[i].se;
        }
    }
    cout<<ans<<endl;
}
 

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