#include <algorithm>
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned long long
#define ld long double
#define ff first
#define ss second
#define ln "\n"
#define mp make_pair
#define pb push_back
#define INF (ll)1e18
ll MOD = (ll)(1e9+7);
void dfs(ll u, ll p, vector<vector<ll>> &A, ll &cnt){
if (A[u].size()==1) cnt++;
for (auto v:A[u]){
if (v==p) continue;
dfs(v, u, A, cnt);
}
}
void solve(){
ll n, m; cin >> n >> m;
vector<vector<ll>> A(n+1);
for (ll i=0; i<m; i++){
ll u, v; cin >> u >> v;
A[u].push_back(v); A[v].push_back(u);
}
ll cnt=0; dfs(1, 1, A, cnt);
if (cnt>2 or m>=n){
cout << "NO\n"; return;
}else{
cout << "YES\n";
}
cout << 1 << ln << 1 << ln; return;
if (n==1){
cout << "YES\n1\n1\n"; return;
}else if (n==2){
ll _; cin >> _ >> _;
cout << "YES\n2\n1 1\n"; return;
}
for (ll i=0; i<m; i++){
ll u, v; cin >> u >> v;
}
cout << "YES" << ln;
cout << n*2-2 << ln;
for (ll i=2; i<=n; i++){
cout << i << ' ';
}
for (ll i=n; i>=2; i--){
cout << i << ' ';
}
cout << ln;
}
int main(){
ios_base::sync_with_stdio(false); cin.tie(nullptr);
#ifdef LOCAL
auto start = chrono::high_resolution_clock::now();
#endif
ll testc=1;
// cin >> testc;
for (ll __c=1; __c<=testc; __c++) solve();
#ifdef LOCAL
auto duration = chrono::duration_cast<chrono::microseconds>(chrono::high_resolution_clock::now() - start);
cout << setprecision(0) << fixed << "time: " << (double)duration.count()/1000.0 << " milliseconds" << endl;
#endif
}
