import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeSet;

public class Sample138 {
	public static final int MAX_COUNT = 30;
	private final SortedSet<Integer> set = new TreeSet<Integer>();

	public Sample138() {
		for (int index = 1; index <= MAX_COUNT; index++) {
			set.add(index);
		}
	}
	public void delete(int number) {
		set.remove(number);
	}
	public Set<Integer> calc() {
		return set;
	}

	public static void main(String[] args) {
		BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
		try {
			Sample138 sample = new Sample138();
			for (int index = 0; index < 28; index++) {
				sample.delete(Integer.parseInt(reader.readLine()));
			}
			Set<Integer> result = sample.calc();
			for (int i: result) {
				System.out.println(i);
			}
		} catch (IOException ex) {
			ex.printStackTrace();
		}
	}
}