description: You have an array of integers (initially empty).
  
  You have to perform q queries. Each query is of one of two types: 
  
    * "1 x" — add the element x to the end of the array; 
    * "2 x y" — replace all occurrences of x in the array with y. 
  
  
  
  Find the resulting array after performing all the queries.
  
  Input
  
  The first line contains a single integer q (1 ≤ q ≤ 5 ⋅ 10^5) — the number of queries.
  
  Next q lines contain queries (one per line). Each query is of one of two types: 
  
    * "1 x" (1 ≤ x ≤ 5 ⋅ 10^5); 
    * "2 x y" (1 ≤ x, y ≤ 5 ⋅ 10^5). 
  
  
  
  It's guaranteed that there is at least one query of the first type.
  
  Output
  
  In a single line, print k integers — the resulting array after performing all the queries, where k is the number of queries of the first type.
  
  Examples
  
  Input
  
  
  7
  1 3
  1 1
  2 1 2
  1 2
  1 1
  1 2
  2 1 3
  
  
  Output
  
  
  3 2 2 3 2 
  
  Input
  
  
  4
  1 1
  1 2
  1 1
  2 2 2
  
  
  Output
  
  
  1 2 1 
  
  Input
  
  
  8
  2 1 4
  1 1
  1 4
  1 2
  2 2 4
  2 4 3
  1 2
  2 2 7
  
  
  Output
  
  
  1 3 3 7 
  
  Note
  
  In the first example, the array changes as follows:
  
  [] → [3] → [3, 1] → [3, 2] → [3, 2, 2] → [3, 2, 2, 1] → [3, 2, 2, 1, 2] → [3, 2, 2, 3, 2].
  
  In the second example, the array changes as follows:
  
  [] → [1] → [1, 2] → [1, 2, 1] → [1, 2, 1].
  
  In the third example, the array changes as follows:
  
  [] → [] → [1] → [1, 4] → [1, 4, 2] → [1, 4, 4] → [1, 3, 3] → [1, 3, 3, 2] → [1, 3, 3, 7].
solution: import java.util.*;
  import java.io.*;
  public class ReplaceTheNumbers {
      public static void main(String[] args) throws IOException {
          Reader in = new Reader();
          PrintWriter out = new PrintWriter(System.out);
          
          int Q = in.nextInt();
          List<Integer> list = new ArrayList<>();
          Stack<int[]> stack = new Stack<>();
          for (int q = 0; q < Q; q++) {
              if (in.nextInt() == 1) {
                  list.add(in.nextInt());
              } else {
                  stack.push(new int[]{list.size() - 1, in.nextInt(), in.nextInt()});
              }
          }
          int N = list.size();
          int[] res = new int[N];
          HashMap<Integer, Integer> map = new HashMap<>();
          for (int i = N - 1; i >= 0; i--) {
              while (!stack.isEmpty() && stack.peek()[0] == i) {
                  int[] arr = stack.pop();
                  if (map.containsKey(arr[2])) {
                      map.put(arr[1], map.get(arr[2]));
                  } else {
                      map.put(arr[1], arr[2]);
                  }
              }
              res[i] = map.containsKey(list.get(i)) ? map.get(list.get(i)) : list.get(i);
          }
          for (int i = 0; i < N; i++) {
              out.print(res[i] + (i == N - 1 ? "\n" : " "));
          }
          
          out.close();
      }
      static class Reader {
          BufferedReader in;
          StringTokenizer st;
          public Reader() {
              in = new BufferedReader(new InputStreamReader(System.in));
              st = new StringTokenizer("");
          }
          public String nextLine() throws IOException {
              st = new StringTokenizer("");
              return in.readLine();
          }
          public String next() throws IOException {
              while (!st.hasMoreTokens()) {
                  st = new StringTokenizer(in.readLine());
              }
              return st.nextToken();
          }
          public int nextInt() throws IOException {
              return Integer.parseInt(next());
          }
          public long nextLong() throws IOException {
              return Long.parseLong(next());
          }
      }
      public static void sort(int[] arr) {
          List<Integer> list = new ArrayList<>();
          for (int i : arr) {
              list.add(i);
          }
          Collections.sort(list);
          for (int i = 0; i < arr.length; i++) {
              arr[i] = list.get(i);
          }
      }
  }