#include<iostream>

#include<cstdio>

#include<algorithm>

#include<cstring>

#include<string>

#include<stack>

#include<queue>

#include<deque>

#include<set>

#include<vector>

#include<map>

#include<functional>

#define fst first

#define sc second

#define pb push_back

#define mem(a,b) memset(a,b,sizeof(a))

#define lson l,mid,root<<1

#define rson mid+1,r,root<<1|1

#define lc root<<1

#define rc root<<1|1

#define lowbit(x) ((x)&(-x)) 

using namespace std;

typedef double db;

typedef long double ldb;

typedef long long ll;

typedef unsigned long long ull;

typedef pair<int,int> PI;

typedef pair<ll,ll> PLL;

const db eps = 1e-;

const int mod = 1e9+;

const int maxn = 2e6+;

const int maxm = 2e6+;

const int inf = 0x3f3f3f3f;

int n;

struct node{

    int x, y;

}a[maxn];

bool cmp(node a, node b){

    //if(a.y==b.y)return a.x<b.x;

    return a.y<b.y;

}

int main() {

    scanf("%d", &n);

    for(int i = ; i <= n; i++){

        scanf("%d%d", &a[i].x,&a[i].y);

    }

    sort(a+,a++n,cmp);

    int ans = ;

    int r = a[].y;

    for(int i = ; i <= n; i++){

        if(a[i].x>=r){

            ans++;

            r = a[i].y;

        }

    }

    printf("%d",ans);

    return ;

}