#include <bits/stdc++.h> #define ll long long #define all(x) x.begin(), x.end() #define ve vector #define vi vector<int> #define vvi vector<vector<int>> #define pb push_back using namespace std; template <class T> istream& operator >>(istream&in, vector<T>&v) { for(T&el : v) { in >> el; } return in; } template <class T> ostream& operator <<(ostream&out, vector<T>&v) { out <<"{"; for(T&el : v) { out << el << ' '; } out <<"}"; return out; } int main() { ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0); int n, m; cin >> n >> m; vvi res; for (int i = 0; i < m; ++i) { int u, v; cin >> u >> v; --u, --v; vi ar1 = {u, v}; for (int i = 0; i < n; ++i) { if (i != u && i != v) { ar1.pb(i); } } res.pb(ar1); ar1.clear(); for (int i = n - 1; i >= 0; --i) { if (i != u && i != v) { ar1.pb(i); } } ar1.pb(u); ar1.pb(v); res.pb(ar1); } cout << "YES\n" << res.size() << "\n"; for (vi& x : res) { for (int i : x) cout << i+1 << ' '; cout << "\n"; } }