earthquake

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayDeque;
import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;

public class earthquake {
    public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        int lines = Integer.parseInt(reader.readLine());
        ArrayDeque<List<Integer>> queue = new ArrayDeque<>();
        String output = "";
        int count = 0;
        for (int i = 0; i < lines; i++) {
            List<Integer> array = Arrays.stream(reader.readLine().split("\\s+"))
                    .mapToInt(Integer::valueOf)
                    .boxed()
                    .collect(Collectors.toList());
            queue.offer(array);
        }

        while (queue.size() > 0) {
            boolean isBiggest = true;
            List<Integer> currentWave = queue.poll();
            if (currentWave.size() == 1) {
                output += " " + currentWave.get(0);
                count++;
                continue;
            } else {
                int seismicity = currentWave.get(0);
                for (int i = 1; i < currentWave.size(); i++) {
                    if (seismicity >= currentWave.get(i)) {
                        currentWave.remove(i);
                        i--;
                    } else {
                        output += " " + seismicity;
                        count++;
                        currentWave.remove(0);
                        queue.offer(currentWave);
                        isBiggest = false;
                        break;
                    }
                }
                if (isBiggest) {
                    queue.offer(currentWave);
                }
            }
        }
        System.out.println(count);
        System.out.println(output.trim());
    }
}