#include <fstream>
#include <vector>
using namespace std;
#define N 50005
int n,m,u[N];
vector < int > v[N];
ifstream in ("sortaret.in");
ofstream out ("sortaret.out");


int df(int k)
{
    u[k]=1;
    out<<k<<' ';
    for(int i=0;i<v[k].size();i++)
        if(!u[v[k][i]])
            df(v[k][i]);
    u[k]=0;
}

int main()
{
    int x,y;
    in>>n>>m;
    while(m--)
    {
        in>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    df(1);
    return 0;
}