#include <algorithm>
#include <iostream>
#include <vector>
using std::endl;
using std::pair;
using std::vector;
bool ascSort(const pair<long long, long long> &a,
const pair<long long, long long> &b) {
return a.second < b.second;
}
vector<long long> optimal_points(vector<pair<long long, long long>> &segments) {
vector<long long> points;
long long n = segments.size();
long long count = 0;
while (n != 0) {
auto it1 = segments.begin(); // ---------- changed here
long long firstNum = segments[0].second;
for (long long i = 1; i < n; i++) {
if ((firstNum <= segments[i].second) && (firstNum >= segments[i].first)) {
std::cout << "YAYY" << endl;
} else {
points.push_back(firstNum);
segments.erase(it1, it1 + (i - 1));
break;
}
}
count = count + 1;
}
std::cout << count << endl;
return points;
}
int main() {
long long n;
std::cin >> n;
vector<long long> first;
vector<long long> second;
for (long long i = 0; i < n; i++)
std::cin >> first[i] >> second[i];
vector<pair<long long, long long>> segments;
for (long long i = 0; i < n; i++)
segments.push_back({first[i], second[i]});
std::sort(segments.begin(), segments.end(), ascSort);
vector<long long> points = optimal_points(segments);
std::cout << points.size() << "\n";
for (size_t i = 0; i < points.size(); ++i) {
std::cout << points[i] << " ";
}
}
