#include <iostream>#include <cstdio>using namespace std;struct node {	int v, ne;} edge[100009];int head[10009], vis[100009], cnt = 1;int n, m, x, y;void addedge (int u, int v) {	edge[++cnt].v = v;	edge[cnt].ne = head[u];	head[u] = cnt;}void EulerianP (int x) {	for (int i = head[x]; i != 0; i = edge[i].ne) {		if (!vis[i]) {			vis[i] = 1;			EulerianP (edge[i].v);		}	}	printf ("%d\n", x);}int main(){	scanf ("%d %d", &n, &m);	for (int i = 1; i <= m; i++) {		scanf ("%d %d", &x, &y);		addedge (x, y);		addedge (y, x);	}	EulerianP (1);	return 0;}