import sys
input = sys.stdin.buffer.readline
sys.setrecursionlimit(10 ** 7)
mod = 10 ** 9 + 7


class Combination:
    """
    SIZEが10**6程度以下の二項係数を何回も呼び出したいときに使う
    使い方:
    comb = Combination(SIZE, MOD)
    comb(10, 3) => 120
    """

    def __init__(self, N, MOD=10 ** 9 + 7):
        self.MOD = MOD
        self.__make_factorial_list(N)

    def __call__(self, n, k):
        if k < 0 or k > n:
            return 0
        res = self.fact[n] * self.inv[k] % self.MOD
        res = res * self.inv[n - k] % self.MOD
        return res

    def nPk(self, n, k):
        if k < 0 or k > n:
            return 0
        return self.fact[n] * self.inv[n - k] % self.MOD

    def nHk(self, n, k):
        if k == 0:
            return 1
        return self.__call__(n + k - 1, k)

    def __make_factorial_list(self, N):
        self.fact = [1] * (N + 1)
        self.inv = [1] * (N + 1)
        MOD = self.MOD
        for i in range(1, N + 1):
            self.fact[i] = (self.fact[i - 1] * i) % MOD
        self.inv[N] = pow(self.fact[N], MOD - 2, MOD)
        for i in range(N, 0, -1):
            self.inv[i - 1] = (self.inv[i] * i) % MOD
        return


gx, gy, K = map(int, input().split())
xyn = tuple(tuple(map(int, input().split())) for _ in range(K))
comb = Combination(1000, mod)
fact = comb.fact
inv = comb.inv


def dfs(i, n, x, y, div):
    if i == K:
        if (x, y) == (gx, gy):
            return fact[n] * div % mod
        return 0

    res = 0
    xi, yi, ni = xyn[i]
    for j in range(ni + 1):
        res += dfs(i + 1, n + j, x + j * xi, y + j * yi, div * inv[j])
        res %= mod
    return res


print(dfs(0, 0, 0, 0, 1))