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 E1620{
  	static FastScanner fs = null;
  	static int N = 5*(int)Math.pow(10,5)+7;
  	public static void main(String[] args) {
  		fs = new FastScanner();
  		PrintWriter out = new PrintWriter(System.out);
  		int q = fs.nextInt();
  		int c = 0;
  		Node first[] = new Node[N];
  		Node last[] = new Node[N];
  		for(int i=0;i<q;i++){
  			int id = fs.nextInt();
  			if(id==1){
  				int x = fs.nextInt();
  				Node ne = new Node(c);
  				if(first[x]==null){
  					first[x] = ne;
  					last[x] = ne;
  				}
  				else{
  					last[x].next = ne;
  					last[x] = last[x].next;
  				}
  				c+=1;
  			}
  			else{
  				int x = fs.nextInt();
  				int y = fs.nextInt();
  				if(x==y)
  					continue;
  				if(first[x]!=null){
  					last[x].next = first[y];
  					
  					first[y] = first[x];
  					
  					if (last[y] == null) {
  						last[y] = last[x];
  					}
  					first[x] = last[x] = null;
  				}
  			}
  		}
  		int arr[] = new int[c];
  		for(int i=0;i<N;i++){
  			Node ne = first[i];
  			while (ne!=null) {
  				arr[ne.data] = i;
  				ne = ne.next;
  			}
  		}
  		for(int i=0;i<c;i++){
  			out.print(arr[i]+" ");
  		}
  		out.println();
  		out.close();
  	}
  	static class Node{
  		int data;
  		Node next;
  		Node(int data){
  			this.data = data;
  		}
  	}
  	static void sort(int[] a) {
  		ArrayList<Integer> l=new ArrayList<>();
  		for (int i:a) l.add(i);
  		Collections.sort(l);
  		for (int i=0; i<a.length; i++) a[i]=l.get(i);
  	}
  	static class FastScanner {
  		BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
  		StringTokenizer st=new StringTokenizer("");
  		String next() {
  			while (!st.hasMoreTokens())
  				try {
  					st=new StringTokenizer(br.readLine());
  				} catch (IOException e) {
  					e.printStackTrace();
  				}
  			return st.nextToken();
  		}
  		
  		int nextInt() {
  			return Integer.parseInt(next());
  		}
  		int[] readArray(int n) {
  			int[] a=new int[n];
  			for (int i=0; i<n; i++) a[i]=nextInt();
  			return a;
  		}
  		long nextLong() {
  			return Long.parseLong(next());
  		}
  	}
  }