func_code_string: #include <bits/stdc++.h>   using namespace std;   void trace_() { cerr <<   n ; }   template <typename T1, typename... T2>   void trace_(T1 t1, T2... t2) {     cerr <<     << t1;     trace_(t2...);   }   const long long mxN = 1e3 + 5;   long long n, a, b;   vector<long long> g[mxN];   signed main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     ;     cin >> n;     vector<pair<long long, long long> > v1, v2;     for (long long i = 0; i < n - 3; i++) {       cin >> a >> b;       if (a > b) swap(a, b);       if (a != 1) v1.emplace_back(a, b);     }     sort(v1.begin(), v1.end(),          [](pair<long long, long long> a, pair<long long, long long> b) {            if (a.first == b.first) return a.second > b.second;            return a.first < b.first;          });     for (long long i = 0; i < n - 3; i++) {       cin >> a >> b;       if (a > b) swap(a, b);       g[a].push_back(b);     }     for (long long i = 2; i <= n; i++) {       sort(g[i].begin(), g[i].end());       reverse(g[i].begin(), g[i].end());       for (long long j = 1; j < (long long)(g[i].size()); j++)         v2.emplace_back(1, g[i][j]);       if ((long long)(g[i].size()) >= 1) v2.emplace_back(1, i + 1);     }     cout << (long long)(v1.size()) + (long long)(v2.size()) <<   n ;     for (pair<long long, long long> i : v1)       cout << i.first <<     << i.second <<   n ;     reverse(v2.begin(), v2.end());     for (pair<long long, long long> i : v2)       cout << i.first <<     << i.second <<   n ;   }   