#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<algorithm>
#define INF 0x7fffffff
#define ll long long

using namespace std;

int n,m,x,y,head[1200],cnt,map[1030][1030],d[1030],begin,s[1030],t;

void dfs(int k)
{
	for(register int i = 1; i <= n; i++)
	{
		if(map
 
[k][i] > 0)
		{
			map[k][i] --;
			map[i][k] --;
			dfs(i);
		}
	}
	s[++t] = k;
}

int main()
{
	scanf("%d",&m);
	for(register int i = 1; i <= m; i++)
	{
		scanf("%d%d",&x,&y);
		map[x][y] ++;
		map[y][x] ++;
		n = max(n,x);
		n = max(n,y);
		d[x] ++;
		d[y] ++;
	}
	for(register int i = 1; i <= n; i++)
	{
		if(d[i] % 2 == 1) 
		{
			begin = i;
			break;
		}
	}
	if(begin == 0) begin = 1;
	dfs(begin); 
	for(register int i = t; i >0; i--) printf("%d\n",s[i]);
	printf("\n"); 
	return 0;
}