func_code_string: #include <bits/stdc++.h>   using namespace std;   const int mod = 998244353;   const int M = 3600 + 10;   int w, h, mx, n, r[M], c[M], cntx, cnty;   long long int fac[M], inv[M], g[M][M], f[M][M], ans;   long long int qpow(long long int a, long long int b) {     long long int y = 1;     for (; b; a = a * a % mod, b >>= 1)       if (b & 1) y = y * a % mod;     return y;   }   long long int C(int a, int b) {     return fac[a] * inv[b] % mod * inv[a - b] % mod;   }   long long int cal(int a, int b) {     return g[w][a] * C(w - cnty - 2 * a, b) % mod * f[h][b] % mod *            C(h - cntx - 2 * b, a) % mod * fac[a] % mod * fac[b] % mod;   }   int main(int argc, char const *argv[]) {     scanf( %d%d%d , &h, &w, &n);     for (int i = 1; i <= n; i++) {       int x1, y1, x2, y2;       scanf( %d%d%d%d , &x1, &y1, &x2, &y2);       r[x1] = r[x2] = c[y1] = c[y2] = 1;     }     mx = max(h, w);     fac[0] = 1;     for (int i = 1; i <= mx; i++) fac[i] = fac[i - 1] * i % mod;     inv[mx] = qpow(fac[mx], mod - 2);     for (int i = mx; i >= 1; i--) inv[i - 1] = inv[i] * i % mod;     for (int i = 1; i <= h; i++) cntx += r[i];     for (int i = 1; i <= w; i++) cnty += c[i];     for (int i = 0; i <= h; i++) f[i][0] = 1;     for (int i = 2; i <= h; i++)       for (int j = 1; 2 * j <= i; j++)         if (r[i] || r[i - 1])           f[i][j] = f[i - 1][j];         else           f[i][j] = (f[i - 1][j] + f[i - 2][j - 1]) % mod;     for (int i = 0; i <= w; i++) g[i][0] = 1;     for (int i = 2; i <= w; i++)       for (int j = 1; 2 * j <= i; j++)         if (c[i] || c[i - 1])           g[i][j] = g[i - 1][j];         else           g[i][j] = (g[i - 1][j] + g[i - 2][j - 1]) % mod;     for (int i = 0; i <= h && 2 * i <= w; i++)       for (int j = 0; j <= w && 2 * j <= h; j++)         if (2 * i + j <= w - cnty && i + 2 * j <= h - cntx)           ans = (ans + cal(i, j)) % mod;     printf( %lld n , ans);     return 0;   }   