#include <bits/stdc++.h>
using namespace std;
const long long N = 3605, MOD = 998244353;
long long a[N], b[N], dp[N][N], ct1[N], ct2[N], c[N][N];
void upd(long long &a, long long b) {
  a += b;
  if (a >= MOD) a -= MOD;
}
void solve(long long w[N], long long n, long long ct[N]) {
  for (long long i = 0; i <= n; i++) {
    for (long long j = 0; j <= n; j++) {
      dp[i][j] = 0;
    }
  }
  dp[0][0] = 1;
  for (long long i = 0; i < n; i++) {
    for (long long j = 0; j < n; j++) {
      if (dp[i][j] != 0) {
        upd(dp[i + 1][j], dp[i][j]);
        if (i + 2 <= n && w[i + 1] == 0 && w[i + 2] == 0) {
          upd(dp[i + 2][j + 1], dp[i][j]);
        }
      }
    }
  }
  for (long long i = 0; i <= n; i++) ct[i] = dp[n][i];
}
long long getC(long long x, long long y) {
  if (x < 0 || y < 0) return 0;
  return c[x][y];
}
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(NULL);
  long long h, w, n;
  cin >> h >> w >> n;
  for (long long i = 0; i < n; i++) {
    long long xl, yl, xr, yr;
    cin >> xl >> yl >> xr >> yr;
    a[xl] = 1;
    a[xr] = 1;
    b[yl] = 1;
    b[yr] = 1;
  }
  solve(a, h, ct1);
  solve(b, w, ct2);
  for (long long i = 0; i < N; i++) {
    c[i][0] = 1;
  }
  for (long long i = 0; i < N; i++) {
    c[i][0] = 1;
    for (long long j = 1; j <= i; j++) {
      c[i][j] = c[i][j - 1] * (i - j + 1ll) % MOD;
    }
  }
  long long cz1 = 0, cz2 = 0;
  for (long long i = 1; i <= h; i++) {
    if (a[i] == 0) cz1++;
  }
  for (long long i = 1; i <= w; i++) {
    if (b[i] == 0) cz2++;
  }
  long long ans = 0;
  for (long long i = 0; i <= h; i++) {
    for (long long j = 0; j <= w; j++) {
      ans = (ans + ct1[i] * (long long)ct2[j] % MOD * getC(cz2 - j * 2, i) %
                       MOD * getC(cz1 - i * 2, j)) %
            MOD;
    }
  }
  cout << ans;
  return 0;
}
