#include <cstdio>
#include <stack>
#include <vector>
#include <algorithm>

using namespace std;

stack<int>st;
vector<int>G[100005];
vector<int>::iterator it;


void euler(int nod)
{
    int other,ok,topu;
    while(G[nod].size())
    {
        other=G[nod].back();
        G[nod].pop_back();
        it=find(G[other].begin(),G[other].end(),nod);
        G[other].erase(it);
        nod=other;
    }
}


int main()
{
    freopen("ciclueuler.in","r",stdin);
    freopen("ciclueuler.out","w",stdout);
    int n,m,i,j,x,y,nod;
    scanf("%d%d",&n,&m);
    for(i=1;i<=m;i++)
    {
        scanf("%d%d",&x,&y);
        G[x].push_back(y);
        G[y].push_back(x);
    }
    printf("1 ");
    nod=1;
    do
    {
        euler(nod);
        x=st.top();
        printf("%d ",x);
        st.pop();
    }while(!st.empty());
    return 0;
}