func_code_string: #include <bits/stdc++.h>   using namespace std;   void fast() {     ios_base::sync_with_stdio(NULL);     cin.tie(0);     cout.tie(0);   }   void online_judge() {     freopen( input.txt ,  r , stdin);     freopen( output.txt ,  w , stdout);   }   const int flag_max = 0x3f3f3f3f;   const long long OO = 1e9;   const double EPS = (1e-7);   int dcmp(double x, double y) { return fabs(x - y) <= EPS ? 0 : x < y ? -1 : 1; }   long long gcd(long long a, long long b) { return !b ? a : gcd(b, a % b); }   long long lcm(long long a, long long b) { return (a / gcd(a, b)) * b; }   int n, p;   int F = 0;   map<pair<int, int>, bool> check;   vector<pair<int, int>> pa_ir;   void dfs(int star) {     for (int i = star + 1; i <= n; i++) {       if (!check[{star, i}]) {         F++;         check[{star, i}] = 1;         check[{i, star}] = 1;         pa_ir.push_back({star, i});         dfs(i);       }     }   }   int main() {     fast();     int t;     cin >> t;     while (t--) {       cin >> n >> p;       p = 2 * n + p;       pa_ir.clear();       check.clear();       dfs(1);       sort(((pa_ir).begin()), ((pa_ir).end()));       for (int i = 0; i < p; i++) {         cout << pa_ir[i].first <<     << pa_ir[i].second <<   n ;       }     }     return 0;   }   