#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 3003;
const ll MOD = 1e9+7;
int row, col, n;
ll F[N][N], Fac[N*N], BC[N][N], res;
void init(){
Fac[0] = 1;
for(int i = 1; i <= row*col; i++) Fac[i] = (Fac[i-1]*(ll)i)%MOD;
for(int i = 0; i <= max(row,col); i++) BC[0][i] = 1;
for(int i = 1; i <= max(row,col); i++){
BC[i][i] = 1;
for(int j = i+1; j <= max(row,col); j++){
BC[i][j] = (BC[i-1][j-1]+BC[i][j-1])%MOD;
}
}
}
ll f(int x, int y, int r, int c){
if(F[x][y]) return F[x][y];
if(x==r&&y==c) return 1;
ll ret = 0;
if(x>r) ret = (ret+f(x-1,y,r,c)*Fac[y])%MOD;
if(y>c) ret = (ret+f(x,y-1,r,c)*Fac[x])%MOD;
return F[x][y] = ret;
}
int main()
{
ios_base::sync_with_stdio(0); cin.tie(0);
cin>>row>>col;
init();
cin>>n;
int u = N, v = N, p = 0, q = 0;
for(int i = 1; i <= n; i++){
int x, y;
cin>>x>>y;
u = min(u,x);
v = min(v,y);
p = max(p,x);
q = max(q,y);
}
int x = p-u+1;
int y = q-v+1;
ll need = (Fac[x*y-n]*f(row,col,x,y))%MOD;
res = (BC[u-1][row-x]*BC[v-1][col-y])%MOD;
res = (res*need)%MOD;
cout<<res<<endl;
return 0;
}
