#include<bits/stdc++.h>
using namespace std;
struct sum{
	int a,b;
}suum[1005]; 
bool cmp(sum x,sum y){
	return x.b<y.b;
}
int main()
{
	int n,cnt=1,i=0,j=0;
	scanf("%d",&n);
	for(int i=0;i<n;i++)
	{
		scanf("%d %d",&suum[i].a,&suum[i].b);
	}
	sort(suum,suum+n,cmp);
	for(i=1;i<n;i++)
	{
		if(suum[i].a>=suum[j].b)
		{
			j=i;
			cnt++;
		}
	}
	printf("%d",cnt);
	return 0;
}

#include<bits/stdc++.h>
#include<iostream>
#include<algorithm>
#include<iomanip>
using namespace std;
int x[100000000];
struct Main{
	int kai;
	int jie;
}pp[1001];
int cmp(Main x,Main y){
	return x.jie<y.jie;
}
int main()
{
	int n,tong=1;
	cin>>n;
	for(int i=1;i<=n;i++){
		cin>>pp[i].kai>>pp[i].jie;
	}
	sort(pp+1,pp+n+1,cmp);
	int lian=1;
	for(int i=2;i<=n;i++){
		if(pp[i].kai>=pp[lian].jie){
			tong++;
			lian=i;
		}
	}
	cout<<tong<<endl; 
	return 0;
}

#include <bits/stdc++.h>
using namespace std;
typedef struct {
	int s;
	int f;
}activity;
activity a[1010];
bool cmp(activity a, activity b) {
	return a.f < b.f;
}
 
int main(){
    int n,t = 0;
    cin >> n;
    for (int i = 1; i <= n; i++) {
    	cin >> a[i].s >> a[i].f;
	}
	sort(a + 1, a + n + 1, cmp);
	int min = 1;	//最小结束时间的下标 
	for (int i = 2; i <= n; i++) {	//逐个进行判断下一个活动的开始时间是否与本次活动的结束时间冲突 
		if(a[i].s >= a[min].f) {	//不冲突就计数器加1且最小结束时间下标转移 
			t++;
			min = i;
		}
	}
	cout << t + 1;
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
struct node{
	int b,e;
}a[1005];
bool com(node a,node b){
	return a.e<b.e;
}
int main(){
	std::ios::sync_with_stdio(false);
    int n,sum=1,ll=0;
    cin>>n;
    for(int i=0;i<n;i++) cin>>a[i].b>>a[i].e;
    sort(a,a+n,com);
	for(int i=1;i<n;i++){
		if(a[i].b>=a[ll].e){
			ll=i;
			sum++;
		}
	}
	cout<<sum<<endl;
    return 0;
}

    #include<cstdio>
    #include<cstring>
    #include<cmath>
    #include<algorithm>
    using namespace std;
    struct node{
    	int e,b;
    }a[1003];
    int cmp(node x,node y)
    {
    	return x.e < y.e;
    }
    int main()
    {
    	int n,ans = 0;
    	scanf("%d",&n);
    	for(int i = 1;i <= n;i++)
    	{
    		scanf("%d%d",&a[i].b,&a[i].e);
    	}
    	sort(a + 1,a + n + 1,cmp); 
    	int t = 0;
    	for(int i = 1;i <= n;i++)
    	{
    		if(a[i].b >= t)
    		{
    			ans++;
    			t = a[i].e;
    		}
    	}
    	printf("%d",ans);
    	return 0;	
    }

#include <algorithm>
#include <iostream>
using namespace std;

struct aa {
    int start;
    int end;
};

bool cmp(aa x, aa y) { return x.end <= y.end; }

void greedychoose(int n, aa a[]) {
    int s = 1, i = 1;
    for (int j = 2; j <= n; j++) {
        if (a[j].start >= a[i].end) {
            i = j;
            s++;
        }
    }
    cout << s << endl;
}

int main() {
    int n, i = 1;
    cin >> n;
    aa time[n + 5];
    while (i <= n) {
        cin >> time[i].start >> time[i].end;
        i++;
    }
    sort(time + 1, time + n, cmp);
    greedychoose(n, time);
}

#include <bits/stdc++.h>
using namespace std;
pair<int,int>pa[1005];
bool cmp(pair<int,int>a,pair<int,int>b)
{
	return a.second<b.second;
}
int main()
{
	int n;
	cin>>n;
	for(int i=1;i<=n;++i)
	{
		cin>>pa[i].first>>pa[i].second;
	}
	sort(pa+1,pa+n+1,cmp);
	int cnt = 1;
	int r = pa[1].second;//先确定最小的右边界
	for(int i=1;i<=n;++i)
	{
		if(pa[i].first>=r){
			cnt++;
			r=pa[i].second;//每次匹配成功，将cnt++并且更新新的右边界
		}
	}
	cout << cnt << endl;
}