SP1505 MOLE - Whac-a-Mole

 While visiting a traveling fun fair you suddenly have an urge to break the high score in the Whac-a-Mole game. The goal of the Whac-a-Mole game is to... well... whack moles. With a hammer. To make the job easier you have first consulted the fortune teller and now you know the exact appearance patterns of the moles. The moles appear out of holes occupying the n $ ^{2} $ integer points (x, y) satisfying 0 ≤ x, y

The input consists of several test cases. Each test case starts with a line containing three integers n, d and m, where n and d are as described above, and m is the total number of moles that will appear (1 ≤ n ≤ 20, 1 ≤ d ≤ 5, and 1 ≤ m ≤ 1000). Then follow m lines, each containing three integers x, y and t giving the position and time of the appearance of a mole (0 ≤ x, y < n and 1 ≤ t ≤ 10). No two moles will appear at the same place at the same time. The input is ended with a test case where n = d = m = 0. This case should not be processed.

For each test case output a single line containing a single integer, the maximum possible score achievable.