#include <bits/stdc++.h>
using namespace std;
const long long inf = (long long)2e9;
const long long md = 998244353;
long long dx[] = {1, -1, 0, 0}, dy[] = {0, 0, 1, -1};
long long power(long long a, long long p) {
  long long ans = 1;
  while (p) {
    if (p & 1) ans *= a;
    p /= 2;
    a *= a;
    ans %= md;
    a %= md;
  }
  return ans;
}
long long mdinv(long long a) { return power(a, md - 2); }
const long long N = 3e3 + 650;
long long tr[N], tc[N];
long long takeRow[N][N];
long long takeCol[N][N];
vector<long long> row, col;
long long solRow(long long i, long long t) {
  if (i == row.size() || i == (long long)(row.size()) - 1) {
    return t == 0;
  }
  if (takeRow[i][t] != -1) return takeRow[i][t];
  long long ans = solRow(i + 1, t);
  if (row[i] + 1 == row[i + 1]) ans += solRow(i + 2, t - 1);
  ans %= md;
  return takeRow[i][t] = ans;
}
long long solCol(long long i, long long t) {
  if (i == col.size() || i == (long long)(col.size()) - 1) {
    return t == 0;
  }
  if (takeCol[i][t] != -1) return takeCol[i][t];
  long long ans = solCol(i + 1, t);
  if (col[i] + 1 == col[i + 1]) ans += solCol(i + 2, t - 1);
  ans %= md;
  return takeCol[i][t] = ans;
}
long long fac[N];
long long infac[N];
long long npr(long long n, long long r) {
  if (n < r) return 0;
  long long mu = (infac[n - r]) % md;
  return (fac[n] * mu) % md;
}
signed main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  memset(takeCol, -1, sizeof(takeCol));
  memset(takeRow, -1, sizeof(takeRow));
  fac[0] = fac[1] = 1;
  for (long long i = 2; i < N; i++) {
    fac[i] = (fac[i - 1] * i) % md;
  }
  for (long long i = 0; i < (long long)N; i++) infac[i] = mdinv(fac[i]);
  long long h, w, n;
  cin >> h >> w >> n;
  for (long long i = 0; i < (long long)n; i++) {
    long long a, b;
    cin >> a >> b;
    tr[a] = 1;
    tc[b] = 1;
    cin >> a >> b;
    tr[a] = 1;
    tc[b] = 1;
  }
  for (long long i = 1; i <= h; i++)
    if (!tr[i]) row.push_back(i);
  for (long long i = 1; i <= w; i++)
    if (!tc[i]) col.push_back(i);
  long long ans = 0;
  for (long long r = 0; r <= row.size(); r++) {
    long long rways = solRow(0, r);
    if (!rways) continue;
    for (long long c = 0; c <= col.size(); c++) {
      long long cways = solCol(0, c);
      if (!cways) continue;
      long long remRow = (long long)(row.size()) - 2 * r;
      long long remCol = (long long)(col.size()) - 2 * c;
      long long loc = (rways * cways) % md;
      loc *= npr(remRow, c);
      loc %= md;
      loc *= npr(remCol, r);
      loc %= md;
      ans += loc;
      ans %= md;
    }
  }
  ans = (ans % md + md) % md;
  cout << ans;
}
