#include <bits/stdc++.h>

#ifndef LOCAL
#include "icc.h"
#endif

std::vector<std::vector<int>> gr;
std::vector<int> par;
std::vector<int> nodes;
std::mt19937 rng(std::chrono::steady_clock::now().time_since_epoch().count());
// std::mt19937 rng(2);
int find(int a) { return par[a] < 0 ? a : par[a] = find(par[a]); }

#ifdef LOCAL
namespace iv {
std::array<std::array<bool, 101>, 101> cc;
int na = -1, nb = -1;
int cnt = 0;
int num = 0;
int n;
} // namespace iv

int query(int a, int b, int *A, int *B) {
  ++iv::cnt;
  for (int ii = 0; ii < a; ++ii) {
    int i = A[ii];
    for (int jj = 0; jj < b; ++jj) {
      int j = B[jj];
      if (iv::cc[i][j]) {
        return true;
      }
    }
  }
  return false;
}
bool connected(int a, int b) {
  if (a == b) {
    return true;
  }
  if (par.empty()) {
    return false;
  }
  a = find(a);
  b = find(b);
  return a == b;
}
void newQuery() {
  while (true) {
    int a, b;
    // a = iv::num + 1;
    // b = iv::num + 2;
    if (iv::num == 0) {
      a = (int)(rng() % iv::n) + 1;
      b = (int)(rng() % iv::n) + 1;
    } else {
      int aa = (int)(rng() % iv::n) + 1;
      if (gr[aa].empty()) {
        continue;
      }
      a = gr[aa][rng() % gr[aa].size()];
      int bb = (int)(rng() % iv::n) + 1;
      if (gr[bb].empty()) {
        continue;
      }
      b = gr[bb][rng() % gr[bb].size()];
    }
    if (!connected(a, b)) {
      if (a > b) {
        std::swap(a, b);
      }
      iv::na = a;
      iv::nb = b;
      iv::cc[a][b] = true;
      iv::cc[b][a] = true;
      return;
    }
  }
}
void setRoad(int a, int b) {
  if (a > b) {
    std::swap(a, b);
  }
  ++iv::num;
  std::cerr << "Query " << iv::num << ":" << std::endl;
  std::cerr << "Your answer is: " << a << ' ' << b << std::endl;
  std::cerr << "The correct answer is: " << iv::na << ' ' << iv::nb
            << std::endl;
  std::cerr << std::endl;
  if (iv::na != a || iv::nb != b) {
    std::cerr << "Wrong Answer" << std::endl;
    std::exit(0);
  }
  if (iv::num < iv::n - 1) {
    newQuery();
  }
}
#endif

bool query(std::vector<int> &a, std::vector<int> &b) {
  if (a.empty() || b.empty()) {
    return false;
  }
  return query((int)a.size(), (int)b.size(), a.data(), b.data());
}
bool queryG(std::vector<int> &ag, std::vector<int> &bg) {
  std::vector<int> a, b;
  for (int i : ag) {
    a.insert(a.end(), gr[i].begin(), gr[i].end());
  }
  for (int i : bg) {
    b.insert(b.end(), gr[i].begin(), gr[i].end());
  }
  return query(a, b);
}
void unite(int a, int b) {
  int aa = a, bb = b;
  a = find(a);
  b = find(b);
  if (par[a] > par[b]) {
    std::swap(a, b);
  }
  gr[a].insert(gr[a].end(), gr[b].begin(), gr[b].end());
  gr[b].clear();
  par[a] += par[b];
  par[b] = a;
  setRoad(aa, bb);
}

void run(int N) {
  const int n = N;
  gr.resize(n + 1);
  for (int i = 1; i <= n; ++i) {
    gr[i].push_back(i);
  }
  par.resize(n + 1, -1);

  for (int i = 0; i < n - 1; ++i) {
    // std::vector<int> a, b;
    std::vector<int> seq(std::__lg(n - i) + 1);
    std::iota(seq.begin(), seq.end(), 0);
    std::shuffle(seq.begin(), seq.end(), rng);
    std::vector<int> a, b;
    nodes.clear();
    for (int j = 1; j <= n; ++j) {
      if (!gr[j].empty()) {
        nodes.push_back(j);
      }
    }
    int last = seq.back();
    seq.pop_back();
    bool g = false;
    for (int j : seq) {
      a.clear();
      b.clear();
      // for (int k : nodes) {
      for (int k = 0; k < (int)nodes.size(); ++k) {
        if ((1 << j) & k) {
          a.insert(a.end(), gr[nodes[k]].begin(), gr[nodes[k]].end());
        } else {
          b.insert(b.end(), gr[nodes[k]].begin(), gr[nodes[k]].end());
        }
      }
      if (query(a, b)) {
        g = true;
        break;
      }
    }
    if (!g) {
      a.clear();
      b.clear();
      for (int k = 0; k < (int)nodes.size(); ++k) {
        if ((1 << last) & k) {
          a.insert(a.end(), gr[nodes[k]].begin(), gr[nodes[k]].end());
        } else {
          b.insert(b.end(), gr[nodes[k]].begin(), gr[nodes[k]].end());
        }
      }
      assert(query(a, b));
    }
    std::vector<int> aa = a, bb = b;

    while ((int)a.size() > 1) {
      std::vector<int> na1(a.begin(), a.begin() + a.size() / 2),
          na2(a.begin() + a.size() / 2, a.end());
      if (query(na2, b)) {
        a = na2;
      } else {
        a = na1;
      }
    }
    while ((int)b.size() > 1) {
      std::vector<int> nb1(b.begin(), b.begin() + b.size() / 2),
          nb2(b.begin() + b.size() / 2, b.end());
      if (query(nb2, a)) {
        b = nb2;
      } else {
        b = nb1;
      }
    }
    unite(a[0], b[0]);
  }
}

#ifdef LOCAL
int main() {
  int n;
  std::cin >> n;
  iv::n = n;
  newQuery();
  run(n);
  std::cerr << "Number of queries used: " << iv::cnt << '\n';
}
#endif