import std.conv, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.container, std.math, std.range, std.regex, std.typecons;
import core.bitop, core.thread;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) throw new EOFException; tokens = readln.split; } auto token = tokens[0]; tokens.popFront; return token; }
int readInt() { return readToken().to!int; }
long readLong() { return readToken().to!long; }
real readReal() { return readToken().to!real; }

void chmin(T)(ref T t, in T f) { if (t > f) t = f; }
void chmax(T)(ref T t, in T f) { if (t < f) t = f; }

int binarySearch(T)(in T[] as, in bool delegate(T) test) { int low = -1, upp = cast(int)(as.length); for (; low + 1 < upp; ) { int mid = (low + upp) >> 1; (test(as[mid]) ? low : upp) = mid; } return upp; }
int lowerBound(T)(in T[] as, in T val) { return as.binarySearch((T a) => (a < val)); }
int upperBound(T)(in T[] as, in T val) { return as.binarySearch((T a) => (a <= val)); }


immutable LIM = 2 * 10^^5 + 10;
immutable MO = 10L^^9 + 7;

long[] inv, fac, invFac;
void prepare() {
  inv = new long[LIM];
  fac = new long[LIM];
  invFac = new long[LIM];
  inv[1] = 1;
  foreach (i; 2 .. LIM) {
    inv[i] = MO - (MO / i) * inv[cast(size_t)(MO % i)] % MO;
  }
  fac[0] = invFac[0] = 1;
  foreach (i; 1 .. LIM) {
    fac[i] = fac[i - 1] * i % MO;
    invFac[i] = invFac[i - 1] * inv[i] % MO;
  }
}


alias Point = Tuple!(int, "x", int, "y");

int H, W;
int N;
Point[] P;

long calc(in Point p, in Point q) {
  const dx = q.x - p.x;
  const dy = q.y - p.y;
  if (dx >= 0 && dy >= 0) {
    return fac[dx + dy] * invFac[dx] % MO * invFac[dy] % MO;
  } else {
    return 0;
  }
}

void main() {
  prepare();
  
  try {
    for (; ; ) {
      H = readInt();
      W = readInt();
      N = readInt();
      P = new Point[N];
      foreach (i; 0 .. N) {
        P[i].x = readInt();
        P[i].y = readInt();
      }
      P.sort();
      P ~= Point(H, W);
      auto dp = new long[N + 1];
      foreach (i; 0 .. N + 1) {
        dp[i] = calc(Point(1, 1), P[i]);
        foreach (j; 0 .. i) {
          (dp[i] -= dp[j] * calc(P[j], P[i])) %= MO;
        }
      }
      auto ans = dp[N];
      ans = (ans % MO + MO) % MO;
      writeln(ans);
    }
  } catch (EOFException e) {
  }
}
