/**
* author: BERNARD B.01
**/
#include <bits/stdc++.h>
using namespace std;
#ifdef B01
#include "deb.h"
#else
#define deb(...)
#endif
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
int n, m;
cin >> n >> m;
vector<vector<int>> g(n);
for (int i = 0; i < m; i++) {
int u, v;
cin >> u >> v;
--u; --v;
g[u].push_back(v);
g[v].push_back(u);
}
if (n == 1) {
cout << "YES" << '\n';
cout << 1 << '\n';
cout << 1 << '\n';
} else if (n == 2) {
cout << "YES" << '\n';
cout << 2 << '\n';
cout << 1 << " " << 1 << '\n';
} else if (n == 3) {
cout << "YES" << '\n';
cout << 2 << '\n';
cout << 2 << " " << 2 << '\n';
} else {
cout << "YES" << '\n';
cout << 5 * n << '\n';
for (int i = 0; i < 5 * n; i++) {
cout << i + 1 << " \n"[i == 5 * n - 1];
}
}
return 0;
}
