#include<cstdio>
#include<vector>
using namespace std;
int n,m,k,x,y,ras[110004];
vector<int > v[100004];
void euler(int nod)
{
    int i=0,x;
    while(i<v[nod].size())
    {
        x=v[nod][i];
        v[nod].erase(v[nod].begin()+i);
        i--;
        for(int j=0;j<v[x].size();j++)
            if(v[x][j]==nod)
            {
                v[x].erase(v[x].begin()+j);
                break;
            }
        euler(x);
        i++;
    }
    ras[++k]=nod;
}
int main()
{
    freopen("ciclueuler.in","r",stdin);
    freopen("ciclueuler.out","w",stdout);
    scanf("%d %d",&n,&m);
    for(int i=1;i<=m;i++)
    {
        scanf("%d %d",&x,&y);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    euler(1);
    for(int i=1;i<=k;i++)
        printf("%d ",ras[i]);
    return 0;
}