using namespace std; #include <bits/stdc++.h> #define rep(i,a,b) for(int i = a; i < b; i++) typedef long long ll; int main() { int n, m; cin >> n >> m; vector<vector<int>> ans; rep(i,0,m) { int a, b; cin >> a >> b; a--; b--; vector<int> here, here2; rep(i,0,n) if (i != a && i != b) { here.push_back(i); here2.push_back(i); } reverse(here2.begin(), here2.end()); here.push_back(a); here.push_back(b); here2.push_back(a); here2.push_back(b); ans.push_back(here); ans.push_back(here2); } cout << ans.size() << endl; for (auto l: ans) { for (auto x : l) cout << x+1 << " "; cout << endl; } }