#include <bits/stdc++.h>
using namespace std;
typedef pair<int, int> ii;
ii v[110];
int r[110];
int signatures(int n)
{
	sort(v, v + n);
	int m = 0, i = 0;
	for (int i = 0; i < n; i++)
	{
		int f = v[i].second;
		while (i < n - 1 && v[i + 1].first <= f)
			i++, f = min(v[i].second, f);
		r[m++] = v[i].first;
	}
	return m;
}
int main()
{
	int n, m;
	cin >> n;
	for (int i = 0; i < n; i++)
		cin >> v[i].first >> v[i].second;
	m = signatures(n);
	cout << m << endl;
	for (int i = 0; i < m; i++)
		cout << (i == 0 ? "" : " ") << r[i];
	cout << endl;
}

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

OAowIDcKMyA5CjUgNgoxIDIKNCA4CjEwIDEzCjExIDE1CjE0IDE2

8
0 7
3 9
5 6
1 2
4 8
10 13
11 15
14 16