#include <cstdio>
#include <vector>
#include <list>
using namespace std;
vector <long> a[100001];
vector <long> :: iterator it;
list <long> q;
long e[500001];
int main () {
	long n,m,x,y,u=0,i;

	freopen ("ciclueuler.in","r",stdin);
	freopen ("ciclueuler.out","w",stdout);

	scanf("%ld%ld",&n,&m);
	for (i=1;i<=m;i++) {
		scanf("%ld%ld",&x,&y);
		a[x].push_back(y);
		a[y].push_back(x);
	}
	q.push_front(1);
	while (!q.empty()) {
		x=q.front();
		if (a[x].empty()==1) {
		    if (q.size()!=1)
                printf("%ld ",x);
			q.pop_front();
        }
        else {
			y=a[x].back();
			a[x].pop_back();
			q.push_front(y);
			for (it=a[y].begin();it!=a[y].end();++it)
				if ((*it)==x) {
					a[y].erase(it);
					break;
				}
        }
	}
    printf ("\n");
	return 0;
}