#include <bits/stdc++.h>
using namespace std;
using namespace rel_ops;
using ll = int64_t;
using Pii = pair<int, int>;
using ull = uint64_t;
using Vi = vector<int>;
void run();
int main() {
  cin.sync_with_stdio(0);
  cin.tie(0);
  cout << fixed << setprecision(10);
  run();
  return 0;
}
int uplg(int n) { return 32 - __builtin_clz(n); }
int uplg(ll n) { return 64 - __builtin_clzll(n); }
using Op = pair<Pii, Pii>;
void moveX(vector<Op>& ops, Pii& pos, int to) {
  while (pos.first != to) {
    if (pos.first < to) {
      ops.push_back({pos, {pos.first + 1, pos.second}});
      pos.first++;
    } else {
      ops.push_back({pos, {pos.first - 1, pos.second}});
      pos.first--;
    }
  }
}
void moveY(vector<Op>& ops, Pii& pos, int to) {
  while (pos.second != to) {
    if (pos.second < to) {
      ops.push_back({pos, {pos.first, pos.second + 1}});
      pos.second++;
    } else {
      ops.push_back({pos, {pos.first, pos.second - 1}});
      pos.second--;
    }
  }
}
vector<Op> compute(int count) {
  vector<Pii> pos(count);
  vector<Op> ops;
  for (auto& p : (pos)) cin >> p.first >> p.second;
  Vi sorted(count);
  iota((sorted).begin(), (sorted).end(), 0);
  sort((sorted).begin(), (sorted).end(),
       [&](int l, int r) { return pos[l].first < pos[r].first; });
  bool cont = true;
  while (cont) {
    cont = false;
    for (int j = (1); j < (count + 1); j++) {
      auto& p = pos[sorted[j - 1]];
      if (p.first == j) continue;
      cont = true;
      int minX = min(j, p.first), maxX = max(j, p.first);
      bool ok = true;
      for (auto& q : (pos))
        if (&q != &p) {
          if (p.second == q.second && q.first >= minX && q.first <= maxX) {
            ok = false;
            break;
          }
        }
      if (ok) moveX(ops, p, j);
    }
  }
  for (int i = (0); i < (count); i++) moveY(ops, pos[i], i + 1);
  for (int i = (0); i < (count); i++) moveX(ops, pos[i], i + 1);
  return ops;
}
void run() {
  int n, m;
  cin >> n >> m;
  auto first = compute(m);
  auto second = compute(m);
  reverse((second).begin(), (second).end());
  cout << int((first).size()) + int((second).size()) << '\n';
  for (auto& e : (first))
    cout << e.first.first << ' ' << e.first.second << ' ' << e.second.first
         << ' ' << e.second.second << '\n';
  for (auto& e : (second))
    cout << e.second.first << ' ' << e.second.second << ' ' << e.first.first
         << ' ' << e.first.second << '\n';
}
