#include <algorithm>
#include <iostream>
#include <vector>
#include <math.h>
#include <set>
#include <map>
#include <string>
#include <stack>
#include <queue>
#include <iomanip>
#include <numeric>
#include <tuple>
#include <bitset>
#include <complex>
#include <unistd.h>
#include <cassert>
#include <cctype>
#include <random>
#include <time.h>
#define _USE_MATH_DEFINES
#define _GLIBCXX_DEBUG
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> plglg;
typedef pair<double, ll> pdlg;
typedef tuple<int, int, int> tiii;
typedef tuple<ll, ll, ll> tlglglg;
typedef tuple<double, double, double> tddd;
typedef complex<double> xy_t;
typedef vector<ll> vll;
typedef vector< vector<ll> > matrix;
#define REP(i, x, y) for(ll i = (ll)x; i < (ll)y; i++)
#define DREP(i, x, y, d) for(ll i = (ll)x; i < (ll)y; i += (ll)d)
#define PER(i, x, y) for(ll i = (ll)x; i > (ll)y; i--)
#define DPER(i, x, y, d) for(ll i = (ll)x; i > (ll)y; i -= (ll)d)
int dx[4] = {1, 0, -1, 0};
int dy[4] = {0, 1, 0, -1};
double pi = 3.141592653589793;
ll mod = 1000000007;
int intmax = 2147483647;
int intmin = -2147483648;
ll llmax = 9223372036854775807;
ll llmin = -9223372036854775807;
int iinf = intmax / 8;
ll inf = llmax / 8;
double eps = 1e-12;

ll modadd(ll x, ll y) {
    return ((x + y) % mod + mod) % mod;
}

ll modminus(ll x, ll y) {
    return ((x - y) % mod + mod) % mod;
}

ll multiply(ll x, ll y) {
    return (x % mod) * (y % mod) % mod;
}

ll modpower(ll x, ll y) {
    if (y == 0) {
        return 1;
    } else if (y == 1) {
        return x % mod;
    } else if (y % 2 == 0) {
        ll p = modpower(x, y / 2);
        return p * p % mod;
    } else {
        ll p = modpower (x, y / 2);
        return (p * p) % mod * (x % mod) % mod;
    }
}

ll divide(ll x, ll y) {
    return multiply(x, modpower(y, mod - 2));
}

ll frac[1000000];
ll invfrac[1000000];

void fracinvfrac(ll n) {
    frac[0] = 1;
    for (int i = 1; i <= n; i++) {
        frac[i] = multiply(frac[i - 1], i);
    }
    invfrac[n] = divide(1, frac[n]);
    for (int i = n - 1; i >= 0; i--) {
        invfrac[i] = multiply(invfrac[i + 1], i + 1);
    }
}

ll modcombi(ll x, ll y) {
    if (x < y || y < 0) {
        return 0;
    } else if (y == 0) {
        return 1;
    } else {
        return multiply(multiply(frac[x], invfrac[x - y]), invfrac[y]);
    }
}

ll dp[3010][2];

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    fracinvfrac(300000);
    ll H, W, N;
    cin >> H >> W >> N;
    plglg pt[N + 1];
    REP(i, 0, N) {
        ll r, c;
        cin >> r >> c;
        pt[i] = plglg(r - 1, c - 1);
    }
    pt[N] = plglg(0, 0);
    sort(pt, pt + N + 1);
    dp[0][0] = 1;
    ll ans = modcombi(H + W - 2, H - 1);
    REP(i, 0, N + 1){
        REP(j, 0, i) {
            if (pt[j].first <= pt[i].first && pt[j].second <= pt[i].second) {
                ll x = pt[i].first - pt[j].first;
                ll y = pt[i].second - pt[j].second;
                ll num = modcombi(x + y, y);
                REP(k, 0, 2) {
                    dp[i][1 - k] = modadd(dp[i][1 - k], multiply(dp[j][k], num));
                }
            }
        }
        if (i > 0) {
            ll ptx = pt[i].first;
            ll pty = pt[i].second;
            ll tmp = modcombi(H - 1 - ptx + W - 1 - pty, H - 1 - ptx);
            ans = modadd(ans, multiply(dp[i][0], tmp));
            ans = modminus(ans, multiply(dp[i][1], tmp));
        }
    }
    // REP(i, 0, 2) {
    //     REP(j, 0, N + 1) {
    //         cout << dp[j][i] << " ";
    //     }
    //     cout << endl;
    // }
    cout << ans << endl;
}


Measured memory_bytes: 8448