#include <bits/stdc++.h> using namespace std; using ll = long long; using vi = vector<int>; using vvi = vector<vi>; using pii = pair<int ,int>; using vpii = vector<pair<int, int>>; using pipii = pair<int, pii>; int p[100]; void solve() { int n, m, a, b; cin >> n >> m; cout << "YES\n" << m * 2 << endl; for (int i = 1; i <= n; i++) p[i] = i; for (int i = 0; i < m; i++) { cin >> a >> b; for(int j = 1; j <= n; j++) { if(j != a && j != b) cout << j << ' '; } cout << a << ' ' << b << ' ' << endl; cout << a << ' ' << b << ' '; for(int j = n; j >= 1; j--) { if(j != a && j != b) cout << j << ' '; } cout << endl; // for (int i = 1; i <= n; i++) cout << p[i] << ' '; // cout << endl; // swap(p[a], p[b]); // for (int i = n; i >= 1; i--) cout << p[i] << ' '; // cout << endl; // if (a < b) swap(p[a], p[b]); } } int main() { ios::sync_with_stdio(false); cin.tie(0); solve(); return 0; }