#include <bits/stdc++.h>
using namespace std;
template <typename T1, typename T2>
inline void chkmin(T1 &x, T2 y) {
  if (x > y) x = y;
}
template <typename T1, typename T2>
inline void chkmax(T1 &x, T2 y) {
  if (x < y) x = y;
}
template <typename T, typename U>
inline ostream &operator<<(ostream &_out, const pair<T, U> &_p) {
  _out << _p.first << ' ' << _p.second;
  return _out;
}
template <typename T, typename U>
inline istream &operator>>(istream &_in, pair<T, U> &_p) {
  _in >> _p.first >> _p.second;
  return _in;
}
template <typename T>
inline ostream &operator<<(ostream &_out, const vector<T> &_v) {
  if (_v.empty()) {
    return _out;
  }
  _out << _v.front();
  for (auto _it = ++_v.begin(); _it != _v.end(); ++_it) {
    _out << ' ' << *_it;
  }
  return _out;
}
template <typename T>
inline istream &operator>>(istream &_in, vector<T> &_v) {
  for (auto &_i : _v) {
    _in >> _i;
  }
  return _in;
}
template <typename T>
inline ostream &operator<<(ostream &_out, const set<T> &_s) {
  if (_s.empty()) {
    return _out;
  }
  _out << *_s.begin();
  for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) {
    _out << ' ' << *_it;
  }
  return _out;
}
template <typename T>
inline ostream &operator<<(ostream &_out, const multiset<T> &_s) {
  if (_s.empty()) {
    return _out;
  }
  _out << *_s.begin();
  for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) {
    _out << ' ' << *_it;
  }
  return _out;
}
template <typename T>
inline ostream &operator<<(ostream &_out, const unordered_set<T> &_s) {
  if (_s.empty()) {
    return _out;
  }
  _out << *_s.begin();
  for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) {
    _out << ' ' << *_it;
  }
  return _out;
}
template <typename T>
inline ostream &operator<<(ostream &_out, const unordered_multiset<T> &_s) {
  if (_s.empty()) {
    return _out;
  }
  _out << *_s.begin();
  for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) {
    _out << ' ' << *_it;
  }
  return _out;
}
template <typename T, typename U>
inline ostream &operator<<(ostream &_out, const map<T, U> &_m) {
  if (_m.empty()) {
    return _out;
  }
  _out << '(' << _m.begin()->first << ": " << _m.begin()->second << ')';
  for (auto _it = ++_m.begin(); _it != _m.end(); ++_it) {
    _out << ", (" << _it->first << ": " << _it->second << ')';
  }
  return _out;
}
template <typename T, typename U>
inline ostream &operator<<(ostream &_out, const unordered_map<T, U> &_m) {
  if (_m.empty()) {
    return _out;
  }
  _out << '(' << _m.begin()->first << ": " << _m.begin()->second << ')';
  for (auto _it = ++_m.begin(); _it != _m.end(); ++_it) {
    _out << ", (" << _it->first << ": " << _it->second << ')';
  }
  return _out;
}
const string FILENAME = "input";
const int MAXN = 55;
int n, m;
int xa[MAXN], xb[MAXN], ya[MAXN], yb[MAXN];
int q[MAXN];
vector<tuple<int, int, int, int>> moves;
bool comp(int i, int j) { return xa[i] < xa[j]; }
bool comp1(int i, int j) { return yb[i] < yb[j]; }
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cin >> n >> m;
  for (int i = 0; i < m; i++) {
    cin >> xa[i] >> ya[i];
    xa[i]--, ya[i]--;
  }
  for (int i = 0; i < m; i++) {
    cin >> xb[i] >> yb[i];
    xb[i]--, yb[i]--;
  }
  for (int i = 0; i < m; i++) {
    q[i] = i;
  }
  sort(q, q + m, comp);
  for (int i = 0; i < m; i++) {
    int j = q[i];
    while (xa[j] > i) {
      moves.emplace_back(xa[j], ya[j], xa[j] - 1, ya[j]);
      xa[j]--;
    }
  }
  for (int i = m - 1; i >= 0; i--) {
    int j = q[i];
    while (xa[j] < i) {
      moves.emplace_back(xa[j], ya[j], xa[j] + 1, ya[j]);
      xa[j]++;
    }
  }
  sort(q, q + m, comp1);
  for (int i = 0; i < m; i++) {
    int j = q[i];
    while (ya[j] != i) {
      if (ya[j] > i) {
        moves.emplace_back(xa[j], ya[j], xa[j], ya[j] - 1);
        ya[j]--;
      } else {
        moves.emplace_back(xa[j], ya[j], xa[j], ya[j] + 1);
        ya[j]++;
      }
    }
  }
  for (int i = 0; i < m; i++) {
    while (xa[i] != xb[i]) {
      if (xa[i] > xb[i]) {
        moves.emplace_back(xa[i], ya[i], xa[i] - 1, ya[i]);
        xa[i]--;
      } else {
        moves.emplace_back(xa[i], ya[i], xa[i] + 1, ya[i]);
        xa[i]++;
      }
    }
  }
  for (int i = 0; i < m; i++) {
    int j = q[i];
    while (ya[j] > yb[j]) {
      moves.emplace_back(xa[j], ya[j], xa[j], ya[j] - 1);
      ya[j]--;
    }
  }
  for (int i = m - 1; i >= 0; i--) {
    int j = q[i];
    while (ya[j] < yb[j]) {
      moves.emplace_back(xa[j], ya[j], xa[j], ya[j] + 1);
      ya[j]++;
    }
  }
  cout << (int)(moves).size() << '\n';
  for (auto x : moves) {
    cout << get<0>(x) + 1 << ' ' << get<1>(x) + 1 << ' ' << get<2>(x) + 1 << ' '
         << get<3>(x) + 1 << '\n';
  }
  return 0;
}
