#include <iostream>
#include <algorithm>
#include <vector>

using namespace std;

const int MOD = 1000000007;
const int valMax = 2 * 100005;

long long fact[valMax];

long long power(long long base, long long exp)
{
    if(exp == 0)
        return 1;
    if(exp % 2 == 0)
    {
        long long x = power(base, exp / 2);
        return (x * x) % MOD;
    }
    return (base * power(base, exp - 1)) % MOD;
}

inline long long invers(long long x)
{
    return power(x, MOD - 2);
}

void CalcFact()
{
    fact[0] = 1;
    for(int i = 1; i < valMax; ++i)
        fact[i] = (fact[i-1] * i) % MOD;
}

long long comb(long long n, long long k)
{
    return (fact[n] * invers((fact[k] * fact[n-k]) % MOD)) % MOD;
}

inline long long Paths(int x, int y) //drumuri de la 1,1 la x,y
{
    return comb(x + y - 2, x - 1);
}

int main()
{
    CalcFact();
    int h, w, n;
    cin >> h >> w >> n;
    vector<pair<int, int> > black(n);
    for(int i = 0; i < n; ++i)
        cin >> black[i].first >> black[i].second;
    n++;
    black.push_back(make_pair(h, w));
    sort(black.begin(), black.end());
    vector<long long> dp(n);
    dp[0] = Paths(black[0].first, black[0].second);
    for(int i = 1; i < n; ++i)
    {
        dp[i] = Paths(black[i].first, black[i].second);
        for(int j = 0; j < i; ++j)
        {
            dp[i] -= (dp[j] * Paths(black[i].first - black[j].first + 1, black[i].second - black[j].second + 1)) % MOD;
            if(dp[i] < 0)
                dp[i] += MOD;
        }
    }
    cout << dp.back();
    return 0;
}