/* Author : Mychecksdead */
#include<bits/stdc++.h>
using namespace std;
#define ll long long int
#define MOD (1000000000+7)
#define MOD1 (998244353)
#define pb push_back
#define all(x) x.begin(), x.end()
#define en cout << '\n'
#define ff first
#define ss second
#define pii pair<int,int>
#define vi vector<int>
const int N = 1e6+100, M = 1e5+10, K = 52, MX = 30;
int n, m, o =0, oo = 0;
vector<int> g[N];
bool no = 0;
vector<int> vis(N);
void dfs(int v, int p){
if(g[v].size() > 2) o++;
else if(g[v].size() == 2) oo++;
for(int u: g[v]){
if(u != p){
dfs(u, v);
}
}
}
void solve(){
cin >> n >> m;
for(int i = 1; i <= m; ++i){
int u, v; cin >> u >> v;
g[u].pb(v);
g[v].pb(u);
}
vis[1] = 1;
if(m >= n){
cout << "NO";
}else{
dfs(1, 1);
if(o > 1){
cout << "NO";
}else{
cout << "YES\n";
cout << "1\n1";
}
}
}
int main(){
cin.tie(0); ios::sync_with_stdio(0);
int tt = 1, aa;
// freopen("in.txt", "r", stdin);
// freopen("out.txt", "w", stdout);
while(tt--){
solve();
}
cerr<<"time taken : "<<(float)clock()/CLOCKS_PER_SEC<<" seconds\n";
return 0;
}
