// C++ includes used for precompiling -*- C++ -*-

// Copyright (C) 2003-2013 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// <http://www.gnu.org/licenses/>.

/** @file stdc++.h
 *  This is an implementation file for a precompiled header.
 */

// 17.4.1.2 Headers

// C
#ifndef _GLIBCXX_NO_ASSERT
#include <cassert>
#endif
#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>

#if __cplusplus >= 201103L
#include <ccomplex>
#include <cfenv>
#include <cinttypes>
// #include <cstdalign>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cwchar>
#include <cwctype>
#endif

// C++
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>

#if __cplusplus >= 201103L
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#endif

using namespace std;
typedef long long ll;

ll a, b, c, m, n, k, x;
string s;
ll Num = 150;

int main()
{
  ll w, h, n;
  cin >> w >> h >> n;
  ll x[Num], y[Num], a[Num];
  ll fig[Num][Num];
  ll s = w, t = h;

  for (ll i = 0; i < n; i++)
  {
    cin >> x[i] >> y[i] >> a[i];
  }

  for (ll i = 0; i < h; i++)
  {
    for (ll j = 0; j < w; j++)
    {
      fig[i][j] = 0;
    }
  }

  for (ll i = 0; i < n; i++)
  {
    switch (a[i])
    {
    case 1:
      for (ll j = 0; j < h; j++)
      {
        for (ll k = 0; k < x[i]; k++)
        {
          fig[j][k] = 1;
        }
      }
      break;
    case 2:
      for (ll j = 0; j < h; j++)
      {
        for (ll k = x[i]; k < w; k++)
        {
          fig[j][k] = 1;
        }
      }
      break;
    case 3:
      for (ll j = 0; j < y[i]; j++)
      {
        for (ll k = 0; k < w; k++)
        {
          fig[j][k] = 1;
        }
      }
      break;
    case 4:
      for (ll j = y[i]; j < h; j++)
      {
        for (ll k = 0; k < w; k++)
        {
          fig[j][k] = 1;
        }
      }
      break;
    }
  }

  ll count = 0;
  for (ll i = 0; i < h; i++)
  {
    for (ll j = 0; j < w; j++)
    {
      if (fig[i][j] != 1)
      {
        count++;
      }
    }
  }
  cout << count << endl;
  return 0;
}


Measured memory_bytes: 384