#include <bits/stdc++.h>

using namespace std; const int maxn = 2e5 + 5, mod = 1e9 + 7; typedef long long ll;

int ginv(int x) { return x == 1 ? 1 : (ll)(mod - mod / x) * ginv(mod % x) % mod; }

int inv[maxn];

int f[maxn], g[maxn];


inline int calc(int n, int m)
{
    if (n < m) swap(n, m);
    f[0] = n + m;
    for (int i = 1; i < m << 1; i++) f[i] = (ll)f[i - 1] * (n + m - i) % mod;
    // cerr << n << ' ' << m << ' ' << g[(m << 1) - 1] << endl;
    g[(m << 1) - 1] = ginv(f[(m << 1) - 1]);
    for (int i = (m << 1) - 2; i >= 0; i--) g[i] = (ll)g[i + 1] * (n + m - (i + 1)) % mod;
    auto C = [&](int x, int y)->int
    {
        if (y == 0) return 1;
        int L = (n + m) - (x - y + 1);
        int R = (n + m) - (x + 1);
        // cerr << n << ' ' << m << ' ' << x << ' ' << y << ' ' << L << ' ' << R << endl;
        return (ll)f[L] * (R < 0 ? 1 : g[R]) % mod;
    };
    int res = 0;
    for (int i = 0; i <= m; i++) res = (res + (ll)C(n + m - i * 2, m - i) * C(n + m - i, i) % mod * inv[i] % mod * inv[m - i]) % mod;
    return res;
}

int N, M, K; pair<int, int> a[maxn];

int F[maxn];

int main()
{
    for (int i = (inv[1] = 1) + 1; i < maxn; i++) inv[i] = (ll)(mod - mod / i) * inv[mod % i] % mod;
    for (int i = inv[0] = 1; i < maxn; i++) inv[i] = (ll)inv[i - 1] * inv[i] % mod;
    scanf("%d%d%d", &N, &M, &K);
    for (int i = 1; i <= K; i++) scanf("%d%d", &a[i].first, &a[i].second), a[i].first--, a[i].second--;
    sort(a + 1, a + K + 1);
    int ans = calc(N, M);
    for (int i = 1; i <= K; i++)
    {
        F[i] = calc(a[i].first, a[i].second);
        for (int j = 1; j < i; j++) if (a[i].first >= a[j].first && a[i].second >= a[j].second)
            F[i] = (F[i] - (ll)F[j] * calc(a[i].first - a[j].first, a[i].second - a[j].second)) % mod;
        ans = (ans - (ll)F[i] * calc(N - a[i].first, M - a[i].second)) % mod;
    }
    return 0 * printf("%d\n", (ans + mod) % mod);
}