import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;

public class Median {
  public static void main(String[] args) {
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    List<Integer> l = new LinkedList<Integer>();
    try {
      String s = br.readLine();
      while (!s.equals("") && s != null) {
        try {
          l.add(Integer.parseInt(s));
        } catch (NumberFormatException n) {
          System.err.println("Das war keine Zahl.");
        }
        s = br.readLine();
      }
    } catch (IOException i) {
      System.err.println("Fehler beim Lesen.");
    }
    Collections.sort(l);
    System.out.println(l.get(l.size() / 2));
  }
}