func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 2005, M = 200005;   struct node {     int x, y;   } d[N];   int h, w, n, mod = 1e9 + 7;   long long c[M] = {1, 1}, inv[M] = {1, 1}, ni[M] = {1, 1}, f[N];   long long quick_mod(long long a, long long b) {     long long ans = 1;     while (b) {       if (b & 1) ans = ans * a % mod;       b >>= 1;       a = a * a % mod;     }     return ans;   }   void init() {     for (int i = 2; i < M; i++) {       c[i] = c[i - 1] * i % mod;       ni[i] = (mod - mod / i) * ni[mod % i] % mod;       inv[i] = ni[i] * inv[i - 1] % mod;     }   }   long long C(int n, int m) {     if (n < m) return 0;     if (n == m || m == 0) return 1;     return c[n] * inv[m] % mod * inv[n - m] % mod;   }   bool cmp(node a, node b) {     if (a.x != b.x) return a.x < b.x;     return a.y < b.y;   }   int main() {     init();     scanf( %d%d%d , &h, &w, &n);     for (int i = 0; i < n; i++) scanf( %d%d , &d[i].x, &d[i].y);     sort(d, d + n, cmp);     d[n].x = h;     d[n].y = w;     for (int i = 0; i <= n; i++) {       f[i] = C(d[i].x + d[i].y - 2, d[i].x - 1);       for (int j = 0; j < i; j++) {         if (d[j].x > d[i].x || d[j].y > d[i].y) continue;         f[i] = (f[i] -                 f[j] * C(d[i].x - d[j].x + d[i].y - d[j].y, d[i].x - d[j].x)) %                mod;       }       f[i] = (f[i] + mod) % mod;     }     printf( %lld n , f[n]);     return 0;   }   