# include <iostream>
# include <cstdio>
# include <algorithm>
# include <cmath>
# include <vector>
# include <queue>
# include <stack>
#include <ctime>
using namespace std;
vector <int> g[100005];
int  vis[100005];
int idx1= 0;
priority_queue <pair <int, pair< int, int> > > q;
vector <int> ans[2];
int otg=0;
long long otgsum=0;
int parent[100005];
long long weight[100005];
int n,m;
void FINDMAXPATH(int from)
{
    q.push({0,{0,from}});
    weight[from]=0;
    int i,j,v,prev,w;
    while(!q.empty())
    {
        v = q.top().second.second;
        w = q.top().first;
        prev = q.top().second.first;
        q.pop();
        if(vis[v]==idx1)continue;
        vis[v]=idx1;
        weight[v]=w;
        parent[v]=prev;
        for(i=0;i<g[v].size();i++)
        {
            if(vis[g[v][i]]==idx1)continue;
            q.push({w+1,{v,g[v][i]}});
        }
    }
}
int main()
{
      clock_t begin = clock();
     ios_base::sync_with_stdio(false);
    cin.tie(NULL);
       freopen ("maxpath.out","w",stdout);
freopen ("maxpath.in","r",stdin);
cin>>n>>m;
int i,j;
int u,v;
for(i=1;i<=m;i++)
{
    cin>>u>>v;
    g[u].push_back(v);
    g[v].push_back(u);
}
int cur=n;
int p=1,maxs=0;
int br=1;
long long sum=0;
long long sum2=0;
while(cur>1)
{
    idx1++;
      clock_t end = clock();
  double elapsed_secs = double(end - begin) / CLOCKS_PER_SEC;
//  cout<<elapsed_secs<<endl;
  if(elapsed_secs>=3.0)break;
  cur--;
  ans[1-otg].clear();
    FINDMAXPATH(cur);
    p=1;
    maxs=0;
    for(i=1;i<=n;i++)
{
    if(maxs<weight[i]){maxs=weight[i];p=i;}
}
br=1;
sum=0;
while(p!=0)
{
    ans[1-otg].push_back(p);
    sum+=br*p;
    p=parent[p];
    br++;
}
//ans[1-otg].push_back(cur);
sum2=0;
br=1;
for(i=0;i<ans[1-otg].size();i++)
{
    sum2+=br*ans[1-otg][i];
    br++;
}
if(sum>otgsum||sum2>otgsum)
    {otg=1-otg;otgsum=max(sum,sum2);//cout<<cur<<endl<<endl;
}
}




cout<<ans[otg].size()<<endl;
sum=0;
br=1;
for(i=ans[otg].size()-1;i>=0;i--)
{
    sum2+=br*ans[otg][i];
    br++;
}
sum2=0;
br=1;
for(i=0;i<ans[1-otg].size();i++)
{
    sum2+=br*ans[otg][i];
    br++;
}
if(sum2>=sum)
{
    for(i=0;i<ans[otg].size();i++)
        cout<<ans[otg][i]<<endl;
}
else
{
    for(i=ans[otg].size()-1;i>=0;i--)
        cout<<ans[otg][i]<<endl;
}
}