#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>
using namespace std;
 
#define NMAX 2000001
#define KMAX 1001
#define MOD 2000003
 
vector < pair <int, int> > v, a;
 
inline void gcd(int a, int b, int &x, int &y)
{
    if(b==0) {
        x=1;
        y=0;
    }
    else {
        int x0,y0;
        gcd(b,a%b,x0,y0);
        x=y0;
        y=x0-(a/b)*y0;
    }
}
 
inline int inverse(int a)
{
    int x,y;
    gcd(a,MOD,x,y);
    while(x<=0) 
        x=x+MOD;
    if(x==MOD)
        x=0;
    return x;
}
 
int cnt[NMAX],fact[NMAX],inv[NMAX];
 
inline int number(int l1, int c1, int l2, int c2)
{
    int n = (l2 - l1);
    int m = (c2 - c1);
    return (1LL * fact[n + m] * inv[n] * inv[m]) % MOD;
}
 
int main ()
{
    int n,m,k,i,x,y,j;
    ifstream f("padure2.in");
    ofstream g("padure2.out");
    f>>n>>m>>k;
    for(i=1;i<=k;i++) {
        f>>x>>y;
        a.push_back(make_pair(x,y));
    }
    f.close();
    a.push_back(make_pair(n,m));
    sort(a.begin(), a.end());
     
    for(i = 0; i <= k; i++) {
        int ok = 1;
        for(vector <pair <int, int> > :: iterator it = v.begin();it != v.end();it++)
            if(*it == a[i]) {
                ok = 0;
                break;
            }
        if(ok) 
            v.push_back(a[i]);
    }
     
    k = v.size();
     
    fact[0] = 1;
    inv[0] = 1;
    for(i = 1; i <= n + m; i++) {
        fact[i] = (1LL * i * fact[i - 1])%MOD;
        inv[i] = inverse(fact[i]);
    }
    return 0; 
    for(i = 0; i < k; i++) {
        cnt[i] = number(1, 1, v[i].first, v[i].second);
        for(j = 0; j < i; j++) {
            if(v[j].first <= v[i].first && v[j].second <= v[i].second)
                cnt[i] = (cnt[i] - 1LL * (number(v[j].first, v[j].second, v[i].first, v[i].second))*cnt[j] % MOD + MOD)%MOD;
        }
    }
     
    g << cnt[k - 1] << '\n';
    g.close();
    return 0;
}