#include <bits/stdc++.h>
#define Nmax 50005
using namespace std;

ifstream fin("sortaret.in");
ofstream fout("sortaret.out");

vector < int > v[Nmax];

queue <int> q;

bitset < Nmax >b;


void DFS ( int  x )
{
    b[x] = 1;

    fout << x <<'\n';

    int lng =  v[x].size();

    for ( int i = 0; i < lng; i++ )
        if ( b[v[x][i]] == 0 ) DFS(v[x][i]);
}

int main()
{
    int n, m,x ,y ;

    fin >> n >> m;

    for ( int i = 1; i <= m; i++ )
    {
        fin >> x >> y;

        v[x].push_back(y);
        v[y].push_back(x);
    }

    DFS( 1 );
}