#include <bits/stdc++.h>
using namespace std;
template <class C>
void mini(C &a4, C b4) {
  a4 = min(a4, b4);
}
template <class C>
void maxi(C &a4, C b4) {
  a4 = max(a4, b4);
}
template <class TH>
void _dbg(const char *sdbg, TH h) {
  cerr << sdbg << '=' << h << endl;
}
template <class TH, class... TA>
void _dbg(const char *sdbg, TH h, TA... a) {
  while (*sdbg != ',') cerr << *sdbg++;
  cerr << '=' << h << ',';
  _dbg(sdbg + 1, a...);
}
template <class T>
ostream &operator<<(ostream &os, vector<T> V) {
  os << "[";
  for (auto vv : V) os << vv << ",";
  return os << "]";
}
template <class L, class R>
ostream &operator<<(ostream &os, pair<L, R> P) {
  return os << "(" << P.first << "," << P.second << ")";
}
const long long MAX = 51;
long long m, n;
long long sx[MAX], sy[MAX], tx[MAX], ty[MAX];
struct ruch {
  pair<long long, long long> a, b;
};
vector<ruch> res;
void rusz(long long nr, long long dx, long long dy) {
  (nr, dx, dy);
  ruch pom;
  pom.a = make_pair(sx[nr], sy[nr]);
  sx[nr] += dx;
  sy[nr] += dy;
  pom.b = make_pair(sx[nr], sy[nr]);
  res.push_back(pom);
}
int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout << fixed << setprecision(11);
  if (0) cout << fixed << setprecision(6);
  cin >> n >> m;
  for (long long i = (0); i <= ((long long)(m)-1); i++) {
    cin >> sx[i] >> sy[i];
  }
  for (long long i = (0); i <= ((long long)(m)-1); i++) {
    cin >> tx[i] >> ty[i];
  }
  vector<long long> px(m), py(m);
  for (long long i = (0); i <= ((long long)(m)-1); i++) {
    px[i] = i;
    py[i] = i;
  }
  sort((px).begin(), (px).end(),
       [&](long long a, long long b) { return sx[a] < sx[b]; });
  for (long long kt = (0); kt <= ((long long)(m)-1); kt++) {
    long long i = px[kt];
    while (sx[i] > kt + 1) {
      rusz(i, -1, 0);
    }
  }
  for (long long kt = m - 1; kt >= 0; kt--) {
    long long i = px[kt];
    while (sx[i] < kt + 1) {
      rusz(i, 1, 0);
    }
  }
  ("krok1");
  sort((py).begin(), (py).end(),
       [&](long long a, long long b) { return ty[a] < ty[b]; });
  for (long long kt = (0); kt <= ((long long)(m)-1); kt++) {
    long long i = py[kt];
    while (sy[i] < kt + 1) {
      rusz(i, 0, 1);
    }
    while (sy[i] > kt + 1) {
      rusz(i, 0, -1);
    }
  }
  ("krok2");
  for (long long i = (0); i <= ((long long)(m)-1); i++) {
    while (sx[i] < tx[i]) {
      rusz(i, 1, 0);
    }
    while (sx[i] > tx[i]) {
      rusz(i, -1, 0);
    }
  }
  ("krok3", sy[0], ty[0]);
  for (long long kt = (0); kt <= ((long long)(m)-1); kt++) {
    long long i = py[kt];
    while (sy[i] > ty[i]) {
      rusz(i, 0, -1);
    }
  }
  for (long long kt = m - 1; kt >= 0; kt--) {
    long long i = py[kt];
    while (sy[i] < ty[i]) {
      rusz(i, 0, 1);
    }
  }
  cout << ((long long)(res).size()) << "\n";
  for (auto el : res) {
    cout << el.a.first << " " << el.a.second << " " << el.b.first << " "
         << el.b.second << "\n";
  }
}
