#pragma GCC optimize ("O3")
#pragma GCC optimize ("unroll-loops")
#pragma GCC target ("avx2")

#include <iostream>
#include <iomanip>
#include <vector>
#include <algorithm>
#include <utility>
#include <string>
#include <queue>
#include <stack>
#include <array>
#include <unordered_set>
#include <random>
#include <cmath>
#include <cassert>

#include <x86intrin.h>

struct xorshift64 {
  unsigned long long int x = 88172645463325252ULL;
  inline unsigned short nextUShort() {
    x = x ^ (x << 7);
    return x = x ^ (x >> 9);
  }
  inline unsigned int nextUShortMod(unsigned long long int mod) {
    x = x ^ (x << 7);
    x = x ^ (x >> 9);
    return ((x & 0x0000ffffffffffff) * mod) >> 48;
  }
  inline unsigned int nextUInt() {
    x = x ^ (x << 7);
    return x = x ^ (x >> 9);
  }
  inline unsigned int nextUIntMod(unsigned long long int mod) {
    x = x ^ (x << 7);
    x = x ^ (x >> 9);
    return ((x & 0x00000000ffffffff) * mod) >> 32;
  }
  inline unsigned long long int nextULL() {
    x = x ^ (x << 7);
    return x = x ^ (x >> 9);
  }
  inline double nextDouble() {
    x = x ^ (x << 7);
    x = x ^ (x >> 9);
    return (double)x * 5.42101086242752217e-20;
  }
};

struct timer {
  double t = 0.0;
  double lastStop = 0.0;
  bool stopped = false;
  timer() {
    restart();
  }
  inline void restart() {
    t = now();
    stopped = false;
  }
  inline void start() {
    if (stopped) {
      t += now() - lastStop;
      stopped = false;
    }
  }
  inline void stop() {
    if (!stopped) {
      lastStop = now();
      stopped = true;
    }
  }
  inline double time() {
    if (stopped) return lastStop - t;
    else return now() - t;
  }
  inline double now() {
    unsigned long long l, h;
    __asm__ ("rdtsc" : "=a"(l), "=d"(h));
    #ifdef LOCAL
    return (double)(l | h << 32) * 2.857142857142857e-10; // 1 / 3.5e9, for local (Ryzen 9 3950X)
    #else
    //return (double)(l | h << 32) * 3.5714285714285715e-10; // 1 / 2.8e9, for AWS EC2 C3 (Xeon E5-2680 v2)
    //return (double)(l | h << 32) * 3.4482758620689656e-10; // 1 / 2.9e9, for AWS EC2 C4 (Xeon E5-2666 v3)
    return (double)(l | h << 32) * 3.333333333333333e-10; // 1 / 3.0e9, for AWS EC2 C5 (Xeon Platinum 8124M / Xeon Platinum 8275CL)
    #endif
  }
};

using namespace std;

typedef long long int ll;
typedef pair<int, int> Pii;

const ll mod = 1000000007;

timer theTimer;
xorshift64 theRandom;
mt19937 theMersenne(1);

// constants
constexpr int turn_limit = 3600;
constexpr int r = 4;

constexpr int n_total = 5400;

constexpr array<int, 5> score_mult = {0, 0, 1, 3, 6};
constexpr int base_score = 200;

// structs
struct room_info {
  int room_host;
  int min_skill;
  int max_skill;
  vector<int> turn_joined;

  room_info(int host_id, int host_skill, int create_turn) {
    this->room_host = host_id;
    this->min_skill = host_skill;
    this->max_skill = host_skill;
    this->turn_joined = vector<int>({create_turn});
  }

  void join(int member_skill, int join_turn) {
    assert((int) this->turn_joined.size() < 4);
    assert(this->turn_joined[this->turn_joined.size()-1] <= join_turn);

    this->min_skill = min(this->min_skill, member_skill);
    this->max_skill = max(this->max_skill, member_skill);
    this->turn_joined.push_back(join_turn);
  }

  int calc_raw_score() {
    int score = (base_score - (max_skill - min_skill) * (max_skill - min_skill)) * score_mult[this->turn_joined.size()];
    for (int i = 0; i < (int) this->turn_joined.size() - 1; i++) {
      for (int j = i + 1; j < (int) this->turn_joined.size(); j++) {
        score -= this->turn_joined[j] - this->turn_joined[i];
      }
    }
    return score;
  }

  int calc_score() {
    int score = calc_raw_score();
    return max(0, score);
  }

  int simulate_score(int member_skill, int join_turn) {
    assert((int) this->turn_joined.size() < 4);
    assert(this->turn_joined[this->turn_joined.size()-1] <= join_turn);

    int temp_min_skill = min(this->min_skill, member_skill);
    int temp_max_skill = max(this->max_skill, member_skill);

    int score = (base_score - (temp_max_skill - temp_min_skill) * (temp_max_skill - temp_min_skill)) * score_mult[this->turn_joined.size() + 1];
    for (int i = 0; i < (int) this->turn_joined.size() - 1; i++) {
      for (int j = i + 1; j < (int) this->turn_joined.size(); j++) {
        score -= this->turn_joined[j] - this->turn_joined[i];
      }
    }
    for (int i = 0; i < (int) this->turn_joined.size(); i++) {
      score -= join_turn - this->turn_joined[i];
    }
    return score;
  }
};

// internals
int turn_count = 0;
vector<vector<room_info> > room_list(5);

vector<int> get_input() {
  int n;
  cin >> n;
  vector<int> added_player(n);
  for (auto &x: added_player) cin >> x;
  return added_player;
}

void output(vector<Pii> op) {
  cout << op.size() << endl;
  for (auto &x: op) cout << x.first << " " << x.second << endl;
}

void solve() {
  auto calc_total_score = [&]() {
    int total_score = 0;
    for (int i = 2; i <= 4; i++) {
      for (auto &room: room_list[i]) total_score += room.calc_score();
    }
    return total_score;
  };

  int current_player_id = 1;
  while (turn_count < turn_limit) {
    auto input = get_input();

    vector<Pii> op;
    for (auto &skill: input) {
      int best_room_score_delta = -1;
      int best_room_idx_i = -1;
      int best_room_idx_j = -1;
      for (int i = 1; i <= 3; i++) {
        for (int j = 0; j < (int) room_list[i].size(); j++) {
          if (max(room_list[i][j].max_skill, skill) - min(room_list[i][j].min_skill, skill) <= 3) {
            int room_score_delta = room_list[i][j].simulate_score(skill, turn_count) - room_list[i][j].calc_score();
            if (room_score_delta > best_room_score_delta) {
              best_room_score_delta = room_score_delta;
              best_room_idx_i = i;
              best_room_idx_j = j;
            }
          }
        }
      }
      if (best_room_idx_i != -1 && best_room_idx_j != -1) {
        op.emplace_back(room_list[best_room_idx_i][best_room_idx_j].room_host, current_player_id);
        room_list[best_room_idx_i][best_room_idx_j].join(skill, turn_count);
        room_list[best_room_idx_i+1].push_back(room_list[best_room_idx_i][best_room_idx_j]);
        swap(room_list[best_room_idx_i][best_room_idx_j], room_list[best_room_idx_i][room_list[best_room_idx_i].size()-1]);
        room_list[best_room_idx_i].pop_back();
      }
      else {
        room_list[1].push_back(room_info(current_player_id, skill, turn_count));
      }
      current_player_id++;
    }

    #ifdef DEBUG
    cerr << "turn_count = " << setw(4) << turn_count << ", score = " << setw(7) << calc_total_score() << endl;
    #endif

    output(op);
    turn_count++;
  }

  cerr << "score = " << calc_total_score() << endl;
}

int main(int argc, char *argv[]) {
  cin.tie(0);
  ios::sync_with_stdio(false);

  int _t, _r;
  cin >> _t >> _r;

  solve();

  return 0;
}