CSES – Movie Festival

#include<bits/stdc++.h>
#define int long long
#define double long double
#define f first
#define s second
#define fastio ios_base::sync_with_stdio(false);cin.tie(0)
using namespace std;
//declare
int n,a,b;
vector<pair<int,int>> v;
//
inline bool cmp(pair<int,int>a, pair<int,int>b){
    return a.s < b.s;
}
signed main(){
    fastio;
    int n;
    cin>>n;
    v.resize(n);
    for(int i=0;i<n;i++){
        cin>>v[i].f>>v[i].s;
    }
    sort(v.begin(),v.end(),cmp);
    int cnt = 1;
    int last = v[0].s;
    for(int i=1;i<n;i++){
        if(v[i].f >= last) cnt++, last = v[i].s;
    }
    cout<<cnt<<"\n";
    return 0;
}