#include <bits/stdc++.h>
using namespace std;
using ll = long long;
template <class t, class u>
void chmax(t& first, u second) {
  if (first < second) first = second;
}
template <class t, class u>
void chmin(t& first, u second) {
  if (second < first) first = second;
}
template <class t>
using vc = vector<t>;
template <class t>
using vvc = vc<vc<t>>;
using pi = pair<ll, ll>;
using vi = vc<ll>;
template <class t, class u>
ostream& operator<<(ostream& os, const pair<t, u>& p) {
  return os << "{" << p.first << "," << p.second << "}";
}
template <class t>
ostream& operator<<(ostream& os, const vc<t>& v) {
  os << "{";
  for (auto e : v) os << e << ",";
  return os << "}";
}
using uint = unsigned;
using ull = unsigned long long;
template <ll i, class T>
void print_tuple(ostream&, const T&) {}
template <ll i, class T, class H, class... Args>
void print_tuple(ostream& os, const T& t) {
  if (i) os << ",";
  os << get<i>(t);
  print_tuple<i + 1, T, Args...>(os, t);
}
template <class... Args>
ostream& operator<<(ostream& os, const tuple<Args...>& t) {
  os << "{";
  print_tuple<0, tuple<Args...>, Args...>(os, t);
  return os << "}";
}
void print(ll x, ll suc = 1) {
  cout << x;
  if (suc == 1) cout << "\n";
  if (suc == 2) cout << " ";
}
ll read() {
  ll i;
  cin >> i;
  return i;
}
vi readvi(ll n, ll off = 0) {
  vi v(n);
  for (ll i = ll(0); i < ll(n); i++) v[i] = read() + off;
  return v;
}
template <class T>
void print(const vector<T>& v, ll suc = 1) {
  for (ll i = ll(0); i < ll(v.size()); i++)
    print(v[i], i == ll(v.size()) - 1 ? suc : 2);
}
string readString() {
  string s;
  cin >> s;
  return s;
}
template <class T>
T sq(const T& t) {
  return t * t;
}
void yes(bool ex = true) {
  cout << "Yes" << endl;
  if (ex) exit(0);
}
void no(bool ex = true) {
  cout << "No" << endl;
  if (ex) exit(0);
}
constexpr ll ten(ll n) { return n == 0 ? 1 : ten(n - 1) * 10; }
const ll infLL = LLONG_MAX / 3;
const ll inf = infLL;
ll topbit(signed t) { return t == 0 ? -1 : 31 - __builtin_clz(t); }
ll topbit(ll t) { return t == 0 ? -1 : 63 - __builtin_clzll(t); }
ll botbit(signed first) { return first == 0 ? 32 : __builtin_ctz(first); }
ll botbit(ll first) { return first == 0 ? 64 : __builtin_ctzll(first); }
ll popcount(signed t) { return __builtin_popcount(t); }
ll popcount(ll t) { return __builtin_popcountll(t); }
bool ispow2(ll i) { return i && (i & -i) == i; }
ll mask(ll i) { return (ll(1) << i) - 1; }
bool inc(ll first, ll second, ll c) { return first <= second && second <= c; }
template <class t>
void mkuni(vc<t>& v) {
  sort(v.begin(), v.end());
  v.erase(unique(v.begin(), v.end()), v.end());
}
ll rand_int(ll l, ll r) {
  static random_device rd;
  static mt19937_64 gen(rd());
  return uniform_int_distribution<ll>(l, r)(gen);
}
void priv(vi s) {
  cout << s.size();
  for (auto i : s) cout << " " << i + 1;
  cout << endl;
}
ll ask(vi s, vi t, ll v) {
  static ll num = 0;
  num++;
  assert(num <= 11111);
  priv(s);
  priv(t);
  cout << v + 1 << endl;
  ll res;
  cin >> res;
  return res;
}
void answer(vc<pi> ans) {
  cout << "ANSWER" << endl;
  for (auto e : ans) cout << e.first + 1 << " " << e.second + 1 << endl;
}
const ll nmax = 510;
vi t[nmax];
bool rem[nmax];
ll tsize(ll v, ll p) {
  ll ret = 1;
  for (auto to : t[v])
    if (to != p && !rem[to]) ret += tsize(to, v);
  return ret;
}
ll findc(ll v, ll p, ll s) {
  ll ret = 1, mx = 0;
  for (auto to : t[v])
    if (to != p && !rem[to]) {
      ll f = findc(to, v, s);
      if (f <= 0)
        return f;
      else {
        ret += f;
        chmax(mx, f);
      }
    }
  chmax(mx, s - ret);
  if (mx * 2 <= s)
    return -v;
  else
    return ret;
}
signed main() {
  cin.tie(0);
  ios::sync_with_stdio(0);
  cout << fixed << setprecision(20);
  ll n;
  cin >> n;
  vi sz(n);
  for (ll i = ll(1); i < ll(n); i++) {
    vi s{0};
    vi tmp(n - 1);
    iota(tmp.begin(), tmp.end(), 1);
    sz[i] = ask(s, tmp, i);
  }
  vi idx(n - 1);
  iota(idx.begin(), idx.end(), 1);
  sort(idx.begin(), idx.end(), [&](ll i, ll j) { return sz[i] > sz[j]; });
  vc<pi> ans;
  for (auto i : idx) {
    memset(rem, 0, sizeof(rem));
    ll cur = 0;
    while (1) {
      cur = -findc(cur, -1, tsize(cur, -1));
      vi vs;
      for (auto to : t[cur])
        if (!rem[to]) vs.push_back(to);
      ll lw = 0, up = vs.size() + 1;
      while (up - lw > 1) {
        const ll m = (lw + up) / 2;
        vi s(vs.begin(), vs.begin() + m);
        if (ask(s, {i}, cur) < m)
          up = m;
        else
          lw = m;
      }
      if (lw == (ll)vs.size()) break;
      rem[cur] = true;
      cur = vs[lw];
    }
    t[cur].push_back(i);
    t[i].push_back(cur);
    ans.emplace_back(cur, i);
  }
  answer(ans);
}
