#include <iostream>
#include <queue>
#include <fstream>
using namespace std;
int viz[100002];
vector<int>graph[100002];

void bfs(int nod)
{   viz[nod]=1;
    queue <int> myq;
    myq.push(nod);
    while(!myq.empty())
    {
        int x=myq.front();
        myq.pop();

        cout<<x<<" ";
        int lim=graph[nod].size();
        for(int i=0; i <lim; i++)
            if(viz[graph[x][i]]==0)
            {
                myq.push(graph[x][i]);
                viz[graph[x][i]]=1;
            }

    }

}

int main()
{
    int n,m;
    ifstream f("bfs.in");
    ofstream g("bfs.out");
    f>>n>>m;
    int k=0;
    for(int i=1; i<=m; i++)
    {
        int a,b;
        f>>a>>b;
        graph[a].push_back(b);
        graph[b].push_back(a);
    }
    bfs(1);
    /*for(int i=1; i<=n; i++)
        if(viz[i]==0)
        {
            bfs(i);
            k++;
        }
    g<<k;*/

    return 0;
}