#include <fstream>
#include <vector>
using namespace std;
#define N 5005
int n,m,u[N];
int a[N][N];
ifstream in ("sortaret.in");
ofstream out ("sortaret.out");


int df(int k)
{
    u[k]=1;
    out<<k<<' ';
    for(int i=1;i<=n;i++)
        if(a[k][i]==1&&u[i]==0)
            df(i);
    u[k]=0;
}

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