Shared code

#include <bits/stdc++.h>
#define mod 1000000007;
#define ll long long
using namespace std;

bool comp(pair<ll, ll> &a, pair<ll, ll> &b)
{
	return a.second < b.second;
}

int main()
{
	int n;
	ll a, b;
	int index = 1;
	cin >> n;
	vector<pair<ll, ll>> movie_times;
	for (int i = 0; i < n; ++i)
	{
		cin >> a >> b;
		movie_times.push_back({a, b});
	}
	sort(movie_times.begin(), movie_times.end(), comp);

	int end_time = movie_times[0].second;
	int start_time = 0;

	int movies_watched = 1;
	int next = 1, prev = 0;
	while (next <= n - 1 && prev <= n - 1)
	{
		if (movie_times[prev].second <= movie_times[next].first)
		{
			movies_watched++;
			next++;
			prev++;
		}
		else
		{
			next++;
		}
	}
	cout << movies_watched;
	return 0;
}