#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
void answer(vector<int> res)
{
if((int)res.size() == 0)
{
cout << "NO\n";
}
else
{
cout << "YES\n";
cout << (int)res.size() << '\n';
for(int r:res) cout << r << ' ';
cout << '\n';
}
}
const int maxN = 1000;
const int INF = 1005;
int N, M;
vector<int> edge[1+maxN];
vector< vector<int> > dist(1+maxN, vector<int>(1+maxN, INF));
int ans = 0;
vector<int> visit;
int S1 = 1, S2 = 1;
int dfs(int u)
{
int F = 0;
for(int v: edge[u])
{
if(visit[v]) continue;
visit[v] = 1;
F = max(F, dfs(v));
}
return 1+F;
}
void dfs1(int s, int u)
{
for(int v: edge[u])
{
if(dist[s][v] <= 1 + dist[s][u]) continue;
dist[s][v] = 1 + dist[s][u];
dfs1(s, v);
}
}
vector<int> leaf(1+maxN, 0);
int main()
{
cin >> N >> M;
if(M > N-1)
{
cout << "NO\n";
return 0;
}
for(int j = 0; j < M; j++)
{
int u, v;
cin >> u >> v;
edge[u].push_back(v);
edge[v].push_back(u);
}
for(int src = 1; src <= N; src++) //CHECK VALIDITY
{
visit = vector<int>(1+N, 0);
ans = 0;
visit[src] = 1;
for(int v: edge[src])
{
visit[v] = 1;
if(dfs(v) >= 3)
ans++;
}
if(ans >= 3)
{
cout << "NO\n";
return 0;
}
}
//VALID!!!
for(int u = 1; u <= N; u++)
{
dist[u][u] = 0;
dfs1(u, u);
}
if(N == 1)
{
answer({1});
return 0;
}
else if(N == 2)
{
answer({1, 1});
return 0;
}
for(int i = 1; i <= N; i++)
{
for(int j = 1; j <= N; j++)
{
if(dist[i][j] > dist[S1][S2])
{
S1 = i;
S2 = j;
}
}
}
S1 = edge[S1][0];
S2 = edge[S2][0];
vector<int> mainline;
for(int i = 1; i <= N; i++)
{
if(dist[S1][i] + dist[i][S2] == dist[S1][S2])
{
mainline.push_back(i);
}
}
sort(mainline.begin(), mainline.end(), [] (int x, int y)
{
return dist[S1][x] < dist[S1][y];
});
vector<int> anslist;
for(int u: mainline)
{
anslist.push_back(u);
for(int v: edge[u])
{
if(edge[v].size() > 1 && dist[S1][v] + dist[v][S2] > dist[S1][S2])
{
anslist.push_back(v);
anslist.push_back(u);
}
}
}
vector<int> J;
for(int q: edge[S2])
{
if(edge[q].size() > 1 && dist[S1][q] + dist[q][S2] > dist[S1][S2])
{
J.push_back(q);
}
}
vector<int> al2 = anslist;
if(al2.size() % 2 == 0) reverse(al2.begin(), al2.end());
if(J.size() > 1)
swap(al2[0], al2[2]);
for(int t: al2) anslist.push_back(t);
answer(anslist);
}
