Problem: During the lunch break all n Berland State University students lined up in the food court. However, it turned out that the food court, too, has a lunch break and it temporarily stopped working.

Standing in a queue that isn't being served is so boring! So, each of the students wrote down the number of the student ID of the student that stands in line directly in front of him, and the student that stands in line directly behind him. If no one stands before or after a student (that is, he is the first one or the last one), then he writes down number 0 instead (in Berland State University student IDs are numerated from 1).

After that, all the students went about their business. When they returned, they found out that restoring the queue is not such an easy task.

Help the students to restore the state of the queue by the numbers of the student ID's of their neighbors in the queue.

Input

The first line contains integer n (2 ≤ n ≤ 2·105) — the number of students in the queue. 

Then n lines follow, i-th line contains the pair of integers ai, bi (0 ≤ ai, bi ≤ 106), where ai is the ID number of a person in front of a student and bi is the ID number of a person behind a student. The lines are given in the arbitrary order. Value 0 is given instead of a neighbor's ID number if the neighbor doesn't exist.

The ID numbers of all students are distinct. It is guaranteed that the records correspond too the queue where all the students stand in some order.

Output

Print a sequence of n integers x1, x2, ..., xn — the sequence of ID numbers of all the students in the order they go in the queue from the first student to the last one.

Examples

Input

4
92 31
0 7
31 0
7 141


Output

92 7 31 141 

Note

The picture illustrates the queue for the first sample.

<image>

Solution (in JAVA):

Solution:
import java.io.*;
import java.math.BigInteger;
import java.math.RoundingMode;
import java.text.DecimalFormat;
import java.util.*;
import java.util.Map.Entry;
	
	
	 public class Palindrome {
	
		static double eps=(double)1e-6;
		static long mod=(int)1e9+7;
		public static void main(String args[]){
			InputReader in = new InputReader(System.in);
			OutputStream outputStream = System.out;
			PrintWriter out = new PrintWriter(outputStream);
			Scanner sc=new Scanner(System.in);
			//----------My Code----------
			
			int n=in.nextInt();
			int a[]=new int[n];
			int b[]=new int[n];
			HashMap<Integer,Integer> hm=new HashMap<>();
			HashMap<Integer,Integer> hm1=new HashMap<>();
			int second=0;
			int secondlast=0;
			for(int i=0;i<n;i++){
				a[i]=in.nextInt();
				b[i]=in.nextInt();	
				if(a[i]==0)
					second=b[i];
				if(b[i]==0)
					secondlast=a[i];
				hm.put(a[i],b[i]);
				hm1.put(b[i],a[i]);
				
			}
			int pos[]=new int[n];
			pos[1]=second;
			pos[n-2]=secondlast;
			int find1=second;
			int find2=secondlast;
			///System.out.println(find1+" "+find2);
			int j=1;
			int k=n-2;
			if(n%2==0){
			for(int i=2;i<n;i+=2){
				
				if(hm.containsKey(find1))
					if(hm.get(find1)!=0){
				pos[(j+=2)%n]=hm.get(find1);
					}
				hm.remove(find1);
				find1=pos[j];
					
				if(hm1.containsKey(find2)){
					if(hm1.get(find2)!=0)
				pos[(k-=2)%n]=hm1.get(find2);
					find2=pos[k];
					hm1.remove(find1);
				}
				
			}
			}
			else
			{
				j=0;
				for(int i=0;i<n;i++){
					if(!hm1.containsKey(a[i])){
						pos[0]=a[i];
						break;
					}
				}
				find1=pos[0];
				for(int i=2;i<n;i+=2){
					
					if(hm.containsKey(find1))
						if(hm.get(find1)!=0){
					pos[(j+=2)%(n)]=hm.get(find1);
						}
					hm.remove(find1);
					find1=pos[j%n];
						
					if(hm1.containsKey(find2)){
						if(hm1.get(find2)!=0)
					pos[(k-=2)%(n)]=hm1.get(find2);
						find2=pos[k%n];
						hm1.remove(find1);
					}
			}
			}
			
			for(int i=0;i<n;i++)
				System.out.println(pos[i]);
			
			//---------------The End------------------
			out.close();
		}
		
			static class TrieNode{
				boolean isLeaf;
				int b;
				TrieNode[] a=new TrieNode[256];
			}
			
			static void insert(String key,TrieNode root){
				TrieNode temp=root;
				for(int i=0;i<key.length();i++){
				//	System.out.println(i);
					
					if(temp.a[key.charAt(i)]==null){
						temp.a[key.charAt(i)]=new TrieNode();
					}
					temp.a[key.charAt(i)].b+=1;
					temp=temp.a[key.charAt(i)];
					
				}
				temp.isLeaf=true;
			}
			static TrieNode search(String key,TrieNode root){
				TrieNode temp=root;
				for(int i=0;i<key.length();i++){
					
					if(temp.a[key.charAt(i)]==null)
						return null;
					temp=temp.a[key.charAt(i)];
					
				}
				return (temp);
			}
			static String max(String key,TrieNode root){
				TrieNode temp=root;
				String res="";
				for(int i=0;i<key.length();i++){
					
					if(temp.a[(key.charAt(i)-'0')^1]!=null){
					//	System.out.println("Hetr");
					temp=temp.a[(key.charAt(i)-'0')^1];
					res+="1";
					}
					else if(temp.a[(key.charAt(i)-'0')]!=null){
						//System.out.println("Hetr");
						temp=temp.a[(key.charAt(i)-'0')];
						res+="0";
					}
				}
			//	System.out.println(res+"jj");
				return res;
			}
			static void remove(String key,TrieNode root){
				TrieNode temp=root;
				for(int i=0;i<key.length();i++){
					if(temp==null)
						return;
				  if(temp.a[(key.charAt(i)-'0')]!=null&&temp.a[key.charAt(i)-'0'].b>1){
						
						temp.a[(key.charAt(i)-'0')].b--;
						
					
					temp=temp.a[(key.charAt(i)-'0')];
				}
				else
				{
					temp.a[key.charAt(i)-'0']=null;
					return;
				}
				}
				if(temp!=null)
					temp.isLeaf=false;
			}
			
			public static void printSorted(TrieNode node, String s) {
		        for (int ch = 0; ch < node.a.length; ch++) {
		            TrieNode child = node.a[ch];
		            if (child != null){
		                printSorted(child, s + (char)(ch));
		            }
		        }
		        if (node.isLeaf) {
		            System.out.println(s);
		        }
		    }
		private static void permutation(String prefix, String str,HashSet<String> hs) {
		    int n = str.length();
		    if (n == 0) hs.add(prefix);
		    else {
		        for (int i = 0; i < n; i++)
		            permutation(prefix + str.charAt(i), str.substring(0, i) + str.substring(i+1, n),hs);
		    }
		}
		
		
		static int recursiveBinarySearch(int[] sortedArray, int start, int end, int key) {
	
			if (start <= end) {
				int mid = start + (end - start) / 2; 
				if (key < sortedArray[mid]) {
					return recursiveBinarySearch(sortedArray, start, mid-1, key);
	
				} else if (key > sortedArray[mid]) {
					return recursiveBinarySearch(sortedArray, mid+1, end , key);
	
				} else {
					return mid;  
				}
			}
			return -(start + 1); 
		}
	
		static long modulo(long a,long b,long c) {
			long x=1;
			long y=a;
			while(b > 0){
				if(b%2 == 1){
					x=(x*y)%c;
				}
			
				y = (y*y)%c; // squaring the base
				b /= 2;
			}
			return  x%c;
		}
		
		
		static long gcd(long x, long y)
		
		{
			long r=0, a, b;
			a = (x > y) ? x : y; // a is greater number
			b = (x < y) ? x : y; // b is smaller number
			r = b;
			while(a % b != 0)
			{
				r = a % b;
				a = b;
				b = r;
			}
			return r;
		}
		static class pair implements Comparable<pair> {
			int x;
			int y;
			//int i;
			pair(int  xx,int yy){
				
				x=xx;
				y=yy;
				//i=ii;
			}
			@Override
			public int compareTo(pair arg0) {
				return Long.compare(this.y, arg0.y);
			}
		
		}
		static class InputReader {
			public BufferedReader reader;
			public StringTokenizer tokenizer;
	
			public InputReader(InputStream inputstream) {
				reader = new BufferedReader(new InputStreamReader(inputstream));
				tokenizer = null;
			}
	
			public String nextLine(){
				String fullLine=null;
				while (tokenizer == null || !tokenizer.hasMoreTokens()) {
					try {
						fullLine=reader.readLine();
					} catch (IOException e) {
						throw new RuntimeException(e);
					}
					return fullLine;
				}
				return fullLine;
			}
			public String next() {
				while (tokenizer == null || !tokenizer.hasMoreTokens()) {
					try {
						tokenizer = new StringTokenizer(reader.readLine());
					} catch (IOException e) {
						throw new RuntimeException(e);
					}
				}
				return tokenizer.nextToken();
			}
			public long nextLong() {
				return Long.parseLong(next());
			}
			public int nextInt() {
				return Integer.parseInt(next());
			}
		}
	}