import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.StringTokenizer;

public class Main {
    public static void main(String[] args) {
        final BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        final BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        try {
            int T = 1;
            for (int i = 0; i < T; ++i) {
                Runner runner = new Runner(br, bw);
                runner.run();
                runner.flush();
            }
            br.close();
            bw.close();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
}

class Solution {
    final int N;
    final Map<String, Integer> users;

    Solution(int N, Map<String, Integer> users) {
        this.N = N;
        this.users = users;
    }

    public String solution() {
        return users.keySet().iterator().next();
    }
}

class Runner {
    final Reader reader;
    final BufferedWriter bw;

    final int N;
    final Map<String, Integer> users;

    Runner(BufferedReader br, BufferedWriter bw) {
        this.reader = new Reader(br);
        this.bw = bw;
        try {
            this.N = Integer.parseInt(br.readLine());
            this.users = new HashMap<>(N, 1);
            for (int n = 0; n < N; ++n) {
                var name = br.readLine();
                users.put(name, users.getOrDefault(name, 0) + 1);
            }
            for (int n = 0; n < N - 1; ++n) {
                var name = br.readLine();
                var v = users.get(name);
                if (v == 1) {
                    users.remove(name);
                } else {
                    users.put(name, v - 1);
                }
            }
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    public void flush() {
        try {
            bw.write('\n');
            bw.flush();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    public void run() throws IOException {
        var res = new Solution(N, users).solution();
        bw.write(String.valueOf(res));
    }
}

class Reader {
    private BufferedReader br;

    public Reader(BufferedReader br) {
        this.br = br;
    }

    public int[] readInts() throws IOException {
        StringTokenizer st = new StringTokenizer(br.readLine(), " ");
        int cnt = st.countTokens();
        int[] ints = new int[cnt];
        for (int i = 0; i < cnt; ++i) {
            ints[i] = Integer.parseInt(st.nextToken());
        }
        return ints;
    }

    public long[] readLongs() throws IOException {
        StringTokenizer st = new StringTokenizer(br.readLine(), " ");
        int cnt = st.countTokens();
        long[] longs = new long[cnt];
        for (int i = 0; i < cnt; ++i) {
            longs[i] = Long.parseLong(st.nextToken());
        }
        return longs;
    }

    public int[][] readIntArrays() throws IOException {
        return br.lines().map(s -> Arrays.stream(s.split(" "))
                .mapToInt(Integer::parseInt)
                .toArray())
                .toArray(int[][]::new);
    }
}