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.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.StringTokenizer;

public class Solution {

	//	public static final double eps = 1e-9;
	//	public static final int mod = 1000000007;
	//	public static final double pi = 3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679;
		public static final int sievesize = (int) (1e6 + 10);
	//	public static boolean[] prime;
	//	public static final int dx[] = {1, -1, 0, 0};
	//	public static final int dy[] = {0, 0, 1, -1};

	public static void main(String[] args) throws IOException {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		InputReader in = new InputReader(inputStream);
		OutputWriter out = new OutputWriter(outputStream);
		Task solver = new Task();
		solver.solve(1, in, out);
		out.close();
	}

	static class Task {

		public void solve(int testNumber, InputReader in, OutputWriter out) throws IOException {
			int n = in.nextInt();
			boolean[] a = new boolean[sievesize], b = new boolean[sievesize];
			int[] store = new int[sievesize];
			int[] res = new int[n];
			for(int i = 0; i < n; i++) {
				int f = in.nextInt(), s = in.nextInt();
				store[f] = s;
				a[f] = true;
				b[s] = true;
			}
			for(int i = 0; i <= sievesize; i++) {
				if(a[i] && !b[i]) {
					res[0] = i;
					break;
				}
			}
			res[1] = store[0];
			for(int i = 2; i < n; i++) {
				res[i] = store[res[i - 2]];
			}
			out.printIntArray(res);
		}

		//        static class Node {
		//        	LinkedList<Integer> list;
		//        	
		//        	public Node() {
		//				list = new LinkedList<>();
		//			}
		//        }
		//        
		//        static class Pair implements Comparable<Pair> {
		//        	
		//        	long first, second;
		//        	
		//        	public Pair(long first, long second) {
		//        		this.first = first;
		//				this.second = second;
		//			}
		//
		//			@Override
		//			public int compareTo(Pair o) {
		//				return (int) (this.second-o.second);
		//			}	
		//        }
	}

	//	public static int[] shuffle(int arr[], Random gen) {
	//		for(int i = 0, n = arr.length; i < n; i++)
	//		{
	//			int index = gen.nextInt(n - i) + i;
	//			int temp = arr[i];
	//			arr[i] = arr[index];
	//			arr[index] = temp;
	//		}
	//		return arr;
	//	}
	//
	//	public static boolean triangle(long a, long b, long c){
	//	    return ((a+b) > c && (b+c) >a && (a+c) > b);
	//	}
	//		
	//	public static boolean isPerfectSquare(long n){
	//		if (n < 0) 
	//	    	return false;
	//	    long test = (long) (Math.sqrt(n) + 0.5);
	//	    return test*test == n;
	//	}
	//		
	//	public static int isnum(char s){
	//		if(s=='1' || s=='2' || s=='3' || s=='4' || s=='5' || s=='6' || s=='7' || s=='8' || s=='9' || s=='0') 
	//	    	return 1; 
	//		return 0;
	//	}
	//		
	//	public static long nextPowerOf2(long n){
	//	    n--;
	//	    n |= n >> 1;
	//	    n |= n >> 2;
	//	    n |= n >> 4;
	//	    n |= n >> 8;
	//	    n |= n >> 16;
	//	    n++;
	//	    return n;
	//	}
	//		
	//	public static int gcd(int a, int b){
	//	    int t; 
	//	    while (b > 0){ 
	//	    	a = a%b; 
	//	    	t = a; 
	//	    	a = b; 
	//	    	b = t; 
	//    	}
	//	    return a;
	//	}
	//		
	//	public static void sieve(int n){
	//		prime=new boolean[sievesize+1];
	//		Arrays.fill(prime, true);
	//	    long x, y; 
	//	    for(x = 2; x * x <= sievesize; x++)
	//	    { 
	//	    	if(prime[(int) x])
	//	    		for(y = x * 2; y <= sievesize; y += x) 
	//	    			prime[(int) y]=false; 
	//	    }
	//	}

	static class InputReader {
		public BufferedReader reader;
		public StringTokenizer tokenizer;

		public InputReader(InputStream stream) {
			reader = new BufferedReader(new InputStreamReader(stream), 32768);
			tokenizer = null;
		}

		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 int nextInt() {
			return Integer.parseInt(next());
		}

		public long nextLong() {
			return Long.parseLong(next());
		}

		public int[] nextIntArray(int size) {
			while (tokenizer == null || !tokenizer.hasMoreTokens()) {
				try {
					tokenizer = new StringTokenizer(reader.readLine());
				} catch (IOException e) {
					throw new RuntimeException(e);
				}
			}
			int[] arr=new int[size];
			for(int i = 0; i < size; i++) 
				arr[i] = Integer.parseInt(tokenizer.nextToken());
			return arr;
		}

		public long[] nextLongArray(int size) {
			while (tokenizer == null || !tokenizer.hasMoreTokens()) {
				try {
					tokenizer = new StringTokenizer(reader.readLine());
				} catch (IOException e) {
					throw new RuntimeException(e);
				}
			}
			long[] arr=new long[size];
			for(int i = 0; i < size; i++) 
				arr[i] = Long.parseLong(tokenizer.nextToken());
			return arr;
		}

		public double[] nextDoubleArray(int size) {
			while (tokenizer == null || !tokenizer.hasMoreTokens()) {
				try {
					tokenizer = new StringTokenizer(reader.readLine());
				} catch (IOException e) {
					throw new RuntimeException(e);
				}
			}
			double[] arr=new double[size];
			for(int i = 0; i < size; i++) 
				arr[i] = Double.parseDouble(tokenizer.nextToken());
			return arr;
		}

		public String[] nextStringArray(int size) throws IOException {
			String[] arr=new String[size];
			for(int i = 0; i < size; i++) 
				arr[i] = reader.readLine();
			return arr;
		}

		public char[] nextCharArray(int size) throws IOException {
			char[] arr=reader.readLine().toCharArray();
			return arr;
		}
	}

	static class OutputWriter {
		public PrintWriter pw;

		public OutputWriter(OutputStream stream) {
			pw = new PrintWriter(stream);
		}

		public void println(Object str) {
			pw.println(str);
		}

		public void print(Object str) {
			pw.print(str + " ");
		}

		public void close() {
			pw.close();
		}

		public void flush() {
			pw.flush();
		}

		public void printStringArray(String[] arr) {
			for(int i = 0; i < arr.length; i++)
				pw.println(arr[i]);
		}

		public void printIntArray(int[] arr) {
			for(int i = 0; i < arr.length; i++)
				pw.print(arr[i] + " ");
		}

		public void printLongArray(long[] arr) {
			for(int i = 0; i < arr.length; i++)
				pw.print(arr[i] + " ");
		}

		public void printCharArray(char[] arr) {
			for(int i = 0; i < arr.length; i++)
				pw.print(arr[i] + " ");
		}

		public void printFloatArray(float[] arr) {
			for(int i = 0; i < arr.length; i++)
				pw.print(arr[i] + " ");
		}

		public void printDoubleArray(double[] arr) {
			for(int i = 0; i < arr.length; i++)
				pw.print(arr[i] + " ");
		}
	}
}