#include <iostream>

#include <vector>
#include <hash_map>
#include <algorithm>
#include <utility>
#include <functional>
using namespace std;

template <typename type> class LIS{
private:
	std::vector<type> vector;
	int DP[50001];
public:
	void insert(type value)
	{
		if (this->vector.empty() || this->vector.back() < value)
		{
			if (!this->vector.empty())
				this->DP[value] = this->vector.back();
			this->vector.push_back(value);
		}
		else
		{
			auto arg = std::lower_bound(this->vector.begin(), this->vector.end(), value);
			*arg = value;
			if (arg != this->vector.begin())
				this->DP[value] = *(--arg);
		}
	}
	std::vector<type> result()
	{
		int res = this->vector.back();
		this->vector.clear();
		while (res != 0){
			vector.push_back(res);
			res = DP[res];
		}
		std::sort(vector.begin(), vector.end());
		return vector;
	}
	unsigned long size()
	{
		return this->vector.size();
	}
};
int main()
{
	long size;
	std::cin >> size;
	std::vector<std::pair<long, long> > vec;
	for (long i = 0; i < size; i++)
	{
		int p, q;
		std::cin >> p >> q;
		vec.push_back({ p, q });
	}
	sort(vec.begin(), vec.end());
	LIS<long> a;
	std::for_each(vec.begin(), vec.end(), [&a](std::pair<long, long> arg){a.insert(arg.second); });
	std::cout << vec.size() - a.size() << std::endl;
	std::vector<long > result = a.result();
	std::for_each(result.begin(), result.end(), [&vec](long args){
		for (std::pair<long, long> & arg : vec)
			if (arg.second == args)
				arg.first = 0;
	});
	std::for_each(vec.begin(), vec.end(), [](std::pair<long, long> arg){ if (arg.first) std::cout << arg.first << std::endl;  });

	return 0;
}