#include <bits/stdc++.h>
using namespace std;

const int N = 11100, M = 51100;
struct edge{int x,y,pre;}a[M*2];int alen,last[N];
void ins(int x,int y){++alen;a[alen]=edge{x,y,last[x]};last[x]=alen;}
vector<int>path;
void oula(int x)
{
    for(int k=last[x];k;k=last[x])
    {
        last[x]=a[k].pre;
		oula(a[k].y);	
    }
	path.push_back(x);
}

int main()
{
    int n,m;scanf("%d%d",&n,&m);
    alen=0;memset(last,0,sizeof(last));
    for(int i=1;i<=m;i++){int x,y;scanf("%d%d",&x,&y);ins(x,y);ins(y,x);}
    oula(1);
    for(int i=path.size();i>=1;i--)printf("%d\n",path[i-1]);
	return 0;
}