java hashMap

import java.util.*;
public class Main {
        public static void main(String[] args) {
            Scanner sc =new Scanner(System.in);
            while (sc.hasNextInt()) {
                int n = sc.nextInt();
                if (n == 1) {
                    continue;
                }
                Map<Integer, Integer> map = new LinkedHashMap<Integer, Integer>();
                int start = sc.nextInt();
                map.put(start, null);
                for (int i = 0; i < n-1; i++) {
                    int next = sc.nextInt();
                    int cur = sc.nextInt();
                    if (map.containsKey(cur)) {
                        map.put(next, map.get(cur));
                    }
                    map.put(cur, next);
                }
                
                int delete = sc.nextInt();
                if (delete == start) {
                    start = map.get(start);
                    map.remove(delete);
                } else {
                     int b = start;
                     int a = map.get(start);
                     for (int i = 0; i < map.size() - 1; i++) {
                         if (a == delete) {
                              map.put(b, map.get(a));
                              map.remove(a);
                             break;
                         } else {
                             b = a; 
                             a = map.get(a);
                          }
                     }    
                    
                    
                }
              
                System.out.print(start);
                int c = start;
                while (map.get(c) != null) {
                      System.out.print(" " + map.get(c));
                      c = map.get(c);
                }
              
            }
        }
}