Problem: Consider a square grid with h rows and w columns with some dominoes on it. Each domino covers exactly two cells of the grid that share a common side. Every cell is covered by at most one domino.

Let's call a placement of dominoes on the grid perfectly balanced if no row and no column contains a pair of cells covered by two different dominoes. In other words, every row and column may contain no covered cells, one covered cell, or two covered cells that belong to the same domino.

You are given a perfectly balanced placement of dominoes on a grid. Find the number of ways to place zero or more extra dominoes on this grid to keep the placement perfectly balanced. Output this number modulo 998 244 353.

Input

The first line contains three integers h, w, and n (1 ≤ h, w ≤ 3600; 0 ≤ n ≤ 2400), denoting the dimensions of the grid and the number of already placed dominoes. The rows are numbered from 1 to h, and the columns are numbered from 1 to w.

Each of the next n lines contains four integers r_{i, 1}, c_{i, 1}, r_{i, 2}, c_{i, 2} (1 ≤ r_{i, 1} ≤ r_{i, 2} ≤ h; 1 ≤ c_{i, 1} ≤ c_{i, 2} ≤ w), denoting the row id and the column id of the cells covered by the i-th domino. Cells (r_{i, 1}, c_{i, 1}) and (r_{i, 2}, c_{i, 2}) are distinct and share a common side.

The given domino placement is perfectly balanced.

Output

Output the number of ways to place zero or more extra dominoes on the grid to keep the placement perfectly balanced, modulo 998 244 353.

Examples

Input


5 7 2
3 1 3 2
4 4 4 5


Output


8


Input


5 4 2
1 2 2 2
4 3 4 4


Output


1


Input


23 42 0


Output


102848351

Note

In the first example, the initial grid looks like this:

<image>

Here are 8 ways to place zero or more extra dominoes to keep the placement perfectly balanced:

<image>

In the second example, the initial grid looks like this:

<image>

No extra dominoes can be placed here.

Solution (in CPP):

Solution:
#include <bits/stdc++.h>
#pragma GCC optimize(3)
using namespace std;
const int INF = 0x3f3f3f3f;
const long long LINF = 0x3f3f3f3f3f3f3f3f;
const int MOD = 998244353;
template <typename S, typename T>
inline bool Min(S &a, const T &b) {
  return a > b ? a = b, true : false;
}
template <typename S, typename T>
inline bool Max(S &a, const T &b) {
  return a < b ? a = b, true : false;
}
template <typename S, typename T>
inline void Adm(S &a, const T &b) {
  a = (a + b) % MOD;
  if (a < 0) a += MOD;
}
template <typename S, typename T>
inline void Mum(S &a, const T &b) {
  a = 1LL * a * b % MOD;
}
template <typename T>
inline bool IsPri(T x) {
  if (x < 2) return false;
  for (T i = 2; i * i <= x; ++i)
    if (x % i == 0) return false;
  return true;
}
template <typename T>
inline T Gcd(T a, T b) {
  while (b) {
    T t = b;
    b = a % b;
    a = t;
  }
  return a;
}
template <typename T>
inline int BitCnt(T x) {
  int cnt = 0;
  while (x) ++cnt, x &= x - 1;
  return cnt;
}
template <typename T>
inline T MDis(T x1, T y1, T x2, T y2) {
  return abs(x1 - x2) + abs(y1 - y2);
}
template <typename T>
inline T MDis(T x1, T y1, T z1, T x2, T y2, T z2) {
  return abs(x1 - x2) + abs(y1 - y2) + abs(z1 - z2);
}
inline double EDis(double x1, double y1, double x2, double y2) {
  return sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2));
}
inline double EDis(double x1, double y1, double z1, double x2, double y2,
                   double z2) {
  return sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2) +
              (z1 - z2) * (z1 - z2));
}
inline long long Pow(long long a, long long n) {
  long long t = 1;
  while (n) {
    if (n & 1) t = t * a % MOD;
    a = a * a % MOD, n >>= 1;
  }
  return t;
}
inline int read() {
  static char buf[1000000], *p1 = buf, *p2 = buf;
  register int x = false;
  register char ch =
      p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, 1000000, stdin), p1 == p2)
          ? EOF
          : *p1++;
  ;
  register bool sgn = false;
  while (ch != '-' && (ch < '0' || ch > '9'))
    ch = p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, 1000000, stdin), p1 == p2)
             ? EOF
             : *p1++;
  ;
  if (ch == '-')
    sgn = true,
    ch = p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, 1000000, stdin), p1 == p2)
             ? EOF
             : *p1++;
  ;
  while (ch >= '0' && ch <= '9')
    x = (x << 1) + (x << 3) + (ch ^ 48),
    ch = p1 == p2 && (p2 = (p1 = buf) + fread(buf, 1, 1000000, stdin), p1 == p2)
             ? EOF
             : *p1++;
  ;
  return sgn ? -x : x;
}
const int N = 4e3 + 100;
bool vx[N], vy[N];
long long f[N][N], g[N][N];
long long fac[N], inv[N];
long long C(long long n, long long m) {
  if (n < m || m < 0) return 0;
  return fac[n] * inv[n - m] % MOD * inv[m] % MOD;
}
int main() {
  fac[0] = inv[0] = 1;
  for (int i = 1; i < N; ++i)
    fac[i] = fac[i - 1] * i % MOD, inv[i] = Pow(fac[i], MOD - 2);
  int n, m, k;
  cin >> n >> m >> k;
  for (int i = 0; i < k; ++i) {
    int x1, y1, x2, y2;
    scanf("%d%d%d%d", &x1, &y1, &x2, &y2);
    vx[x1] = vx[x2] = vy[y1] = vy[y2] = 1;
  }
  int X = 0, Y = 0;
  for (int i = 0; i <= n; ++i) f[i][0] = 1, X += !vx[i];
  for (int i = 1; i <= n; ++i)
    for (int j = 1; j <= i; ++j) {
      f[i][j] = f[i - 1][j];
      if (i >= 2 && !vx[i] && !vx[i - 1]) Adm(f[i][j], f[i - 2][j - 1]);
    }
  for (int i = 0; i <= m; ++i) g[i][0] = 1, Y += !vy[i];
  for (int i = 1; i <= m; ++i)
    for (int j = 1; j <= i; ++j) {
      g[i][j] = g[i - 1][j];
      if (i >= 2 && !vy[i] && !vy[i - 1]) Adm(g[i][j], g[i - 2][j - 1]);
    }
  --X, --Y;
  long long ans = 0;
  for (int i = 0; i * 2 <= X; ++i)
    for (int j = 0; j * 2 <= Y; ++j)
      if (i * 2 + j <= X && i + j * 2 <= Y) {
        long long res = f[n][i] * g[m][j] % MOD;
        res = res * C(X - i * 2, j) % MOD * C(Y - j * 2, i) % MOD;
        res = res * fac[i] % MOD * fac[j] % MOD;
        Adm(ans, res);
      }
  cout << ans << endl;
  return 0;
}