#include <bits/stdc++.h>

using namespace std;

const int maxn=110;
int n, m;
bool susjed[maxn][maxn];
bool bio[maxn];
int k=0;
int v;
vector<int> ve, rj;
int maxi=0;

void dfs(int x) {
	bio[x]=true;
	k++;
	ve.push_back(x);
	v+=x*k;
	
	if (v>maxi) {
		maxi=v;
		rj=ve;
	}
	
	for (int y=0; y<n; y++) {
		if ((susjed[x][y] || susjed[y][x]) && !bio[y]) {
			dfs(y);
		}
	}
	k--;
	v-=x*k;
	ve.pop_back();
}

int main()
{
	
	freopen("maxpath.in", "r", stdin);
	freopen("maxpath.out", "w", stdout);
	
	cin>>n>>m;
	for (int i=0; i<m; i++) {
		int x, y;
		cin>>x>>y;
		susjed[x][y]=true;
		susjed[y][x]=true;
	}
	dfs(1);
	cout<<rj.size()<<'\n';
	for (int i=0; i<rj.size(); i++) {
		cout<<rj[i]<<'\n';
	}
	
}