#include <iostream>
#include <stdio.h>
#include <vector>
#include <algorithm>
#include <cstdio>
#include <ctime>
#define INF 200000000;
using namespace std;
char a[3001][3001];
char res[3001][3001];
int N,M,pr[3001];
char qw[3001];
void prim(int start) {
int n;
int key[3001];
char Q[3001];
int amountInQ=N;
for (int u=0; u<N; u++) {
key[u]=INF;
pr[u]=-1;
Q[u]=1;}
int u,v;
key[start]=0;
while (amountInQ) {
int min=INF;
for (int i=0; i<N; i++) if (Q[i] && key[i]<min) {
u=i; min=key[i]; }
Q[u]=0; amountInQ--;
for (int v=0; v<N; v++)
if (a[u][v]!=0 && Q[v] && a[u][v]<key[v]) {
pr[v]=u;
key[v]=a[u][v]; } }
for (int i=0; i<N; i++)
for (int j=0; j<N; j++) res[i][j]=0;
for (int i=0; i<N; i++)
if (pr[i]!=-1) {
res[i][pr[i]]=1;
res[pr[i]][i]=1; } }
void kek(int u) {
qw[u]=1;
for (int v=0; v<N; v++)
if (a[u][v] && qw[v]==-1)
kek(v);printf("%d\n",u+1);}
int main()
{ scanf("%d%d",&N,&M);
int i,x,y;
for (i=0; i<M; i++) {
scanf("%d%d",&x,&y);
a[--x][--y]=1;
a[y][x]=1; }
prim(0);
for (i=0; i<N; i++) qw[i]=-1;
kek(0); return 0;}