void solve(const int n, const int m, const int k) {
  priority_queue<pair<int, int> > q;
  for (int i = 0; i < n; ++i) {
    q.push(make_pair(0, i));
  }

  for (int i = 0; i < m; ++i) {
    auto a = q.top(); q.pop();
    auto b = q.top(); q.pop();

    cout << a.second + 1 << " " << b.second + 1 << endl;

    a.first--, b.first--;
    q.push(a); q.push(b);
  }
}