#include <bits/stdc++.h>
using namespace std;
void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\'' << x << '\''; }
void __print(const char *x) { cerr << '\"' << x << '\"'; }
void __print(const string &x) { cerr << '\"' << x << '\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }
template <typename T, typename V>
void __print(const pair<T, V> &x) {
  cerr << '{';
  __print(x.first);
  cerr << ',';
  __print(x.second);
  cerr << '}';
}
template <typename T>
void __print(const T &x) {
  int f = 0;
  cerr << '{';
  for (auto &i : x) cerr << (f++ ? "," : ""), __print(i);
  cerr << "}";
}
void _print() { cerr << "]\n"; }
template <typename T, typename... V>
void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v)) cerr << ", ";
  _print(v...);
}
long long f[100009], inv[100009], p[100009];
const long long mod = 998244353;
long long C(int n, int r) {
  if (n < 0 || r < 0 || r > n) return 0;
  return f[n] * inv[r] % mod * inv[n - r] % mod;
}
void pre() {
  f[0] = f[1] = inv[0] = inv[1] = 1;
  for (int i = 2; i <= (100000); ++i)
    f[i] = f[i - 1] * i % mod, inv[i] = mod - inv[mod % i] * (mod / i) % mod;
  for (int i = 2; i <= (100000); ++i) inv[i] = inv[i] * inv[i - 1] % mod;
  p[0] = 1;
  for (int i = 2; i <= (100000); ++i) p[i] = p[i - 2] * C(i, 2) % mod, i++;
}
void solve() {}
bool visx[4001], visy[4001];
long long ans1[4001][4001], ans2[4001][4001];
int main() {
  cin.sync_with_stdio(0);
  cin.tie(0);
  cin.exceptions(cin.failbit);
  pre();
  int h, w, n;
  cin >> h >> w >> n;
  for (int i = 0; i < (n); ++i) {
    int x, y;
    cin >> x >> y;
    visx[x] = 1;
    visy[y] = 1;
    cin >> x >> y;
    visx[x] = 1;
    visy[y] = 1;
  }
  ans1[0][0] = 1;
  ans2[0][0] = 1;
  int cntx = h, cnty = w;
  for (int i = 1; i <= (h); ++i) {
    if (visx[i]) cntx--;
    if (visx[i] || visx[i - 1] || i == 1) {
      for (int j = 0; j < (h + 1); ++j) ans1[i][j] = ans1[i - 1][j];
    } else {
      for (int j = 0; j < (h + 1); ++j)
        ans1[i][j] = (ans1[i - 2][j - 1] + ans1[i - 1][j]) % mod;
    }
  }
  for (int i = 1; i <= (w); ++i) {
    if (visy[i]) cnty--;
    if (visy[i] || visy[i - 1] || i == 1) {
      for (int j = 0; j < (h + 1); ++j) ans2[i][j] = ans2[i - 1][j];
    } else {
      for (int j = 0; j < (h + 1); ++j)
        ans2[i][j] = (ans2[i - 2][j - 1] + ans2[i - 1][j]) % mod;
    }
  }
  long long fns = 0;
  for (int i = 0; i < (h + 1); ++i)
    for (int j = 0; j < (w + 1); ++j) {
      long long cur = ans1[h][i] * ans2[w][j] % mod;
      cur = cur * C(cntx - 2 * i, j) % mod * C(cnty - 2 * j, i) % mod;
      cur = cur * f[i] % mod * f[j] % mod;
      fns += cur;
    }
  cout << fns % mod;
  return 0;
}
