import resource
from copy import copy

# Question: https://yukicoder.me/problems/no/498

DIV_CONST = 1000000007


def trace(goal_x, goal_y, crystals):

    memo = {}

    def local_iter(node):
        if node not in memo:
            (x, y, remain_crystals) = node
            count = 1 if (x, y) == (goal_x, goal_y) else 0
            for crystal in remain_crystals:
                next_x = x + crystal[0]
                next_y = y + crystal[1]
                next_remains = remain_crystals - {crystal}
                if crystal[2] > 1:
                    next_remains = next_remains \
                                   | {(crystal[0], crystal[1], crystal[2] - 1)}
                count = count + local_iter((next_x, next_y, next_remains))

            memo[node] = count

        return memo[node]

    return local_iter((0, 0, crystals))


def load_input(crystal_kinds):
    for l in range(crystal_kinds):
        [x, y, num] = [int(s) for s in raw_input().split()]
        yield (x, y, num)


if __name__ == '__main__':
    # from time import time
    [goal_x, goal_y, crystal_kinds] = [int(s) for s in raw_input().split()]
    # start_time = time()
    crystals = frozenset(load_input(crystal_kinds))
    # proc_time = time() - start_time
    print trace(goal_x, goal_y, crystals)
    # print "time: %f[sec]" % proc_time