#include<bits/stdc++.h>
using namespace std;
int n,e,a[21][21],x,y,c;
void dfs(int x){
	cout<<x<<" ";
	for(int j=1;j<=n;j++){
		if(a[x][j]==1){
			a[x][j]=0;
			a[j][x]=0;
			dfs(j);
		}
	}
}
int main(){
	cin>>n>>e;
	for(int i=1;i<=n;i++){
		cin>>x>>y;
		a[x][y]=1;
		a[y][x]=1;
		a[x][0]++;
		a[y][0]++;
	}
	for(int i=1;i<=n;i++){
		if(a[i][0]%2==1) c++;
	}
	if(c==0) dfs(1);
	else dfs(n),cout<<n;
	
	


	return 0;
}

/**************************************************************
	Problem: 2055
	User: chenpengxi
	Language: C++
	Result: Wrong Answer
****************************************************************/