#include <fstream>

using namespace std;

const int NMAX = 1000000;
const int MOD = 2000003;

int ridica(int a, int b) {
    if (!b)
        return 1;
    else if (b & 1)
        return (1LL * a * ridica(a, b - 1)) % MOD;
    else {
        int aux = ridica(a, b >> 1);
        return (1LL * aux * aux) % MOD;
    }
}

int facts[2 * NMAX + 5];
int inv_facts[2 * NMAX + 5];

void precompute() {
    facts[0] = 1;
    for (int i = 1; i < 2 * NMAX; ++ i)
        facts[i] = (1LL * i * facts[i - 1]) % MOD;

    inv_facts[2 * NMAX - 1] = ridica(facts[2 * NMAX - 1], MOD - 2);
    for (int i = 2 * NMAX - 2; i >= 0; -- i)
        inv_facts[i] = ((i + 1LL) * inv_facts[i + 1]) % MOD;
}

int comb(int a, int b) {
    return ((1LL * facts[a + b] * inv_facts[a]) % MOD * inv_facts[b]) % MOD;
}

const int CMAX = 1005;
int n, m, c;

struct Point {
    int lin, col;

    Point(int _lin = 0, int _col = 0): lin(_lin), col(_col) {}
} v[CMAX];

bool there_is(int lin, int col) {
    for (int i = 1; i <= c; ++ i)
        if (v[i].lin == lin && v[i].col == col)
            return true;
    return false;
}

bool operator<(const Point &a, const Point &b) {
    return a.lin <= b.lin && a.col <= b.col;
}

int dp[CMAX];
bool vis[CMAX];

int compute(int node) {
    if (vis[node])
        return dp[node];
    vis[node] = true;

    dp[node] = comb(n - v[node].lin, m - v[node].col);

    for (int i = 0; i <= c; ++ i)
        if (i != node && v[node] < v[i])
            dp[node] = (dp[node] + MOD - (1LL * compute(i) * comb(v[i].lin - v[node].lin, v[i].col - v[node].col)) % MOD) % MOD;

    return dp[node];
}

int main()
{
    ifstream cin("padure2.in");
    ofstream cout("padure2.out");

    cin >> n >> m >> c;

    for (int i = 1; i <= c; ++ i)
        cin >> v[i].lin >> v[i].col;

    if (there_is(1, 1) || there_is(n, m)) {
        cout << "0\n";

        cin.close();
        cout.close();
        return 0;
    }

    precompute();

    v[0].lin = 1;
    v[0].col = 1;

    cout << compute(0) << '\n';

    cin.close();
    cout.close();
    return 0;
}