#include <stdio.h>
#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
int main()
{
int a, b;
int linenum;
int line_a[10000] = {
0,
};
int line_b[10000] = {
0,
};
int acount = 0, bcount = 0;
int tmp = 0;
cin >> a >> b;
cin >> linenum;
for (int i = 0; i < linenum; i++)
{
cin >> tmp;
if (tmp == 1)
{
cin >> line_a[acount];
acount++;
}
else
{
cin >> line_b[bcount];
bcount++;
}
}
// cout << acount << " " << bcount << "\n";
sort(line_a, line_a + acount);
sort(line_b, line_b + bcount);
line_a[acount] = a;
line_b[bcount] = b;
int maxa = 0;
int maxb = 0;
int memory = 0;
for (int i = 0; i <= acount; i++)
{
// cout << line_a[i] << "\n";
if (maxa < line_a[i] - memory)
{
maxa = line_a[i] - memory;
// cout << maxa << "\n";
}
memory = line_a[i];
}
// cout << "-----\n";
memory = 0;
for (int i = 0; i <= bcount; i++)
{
if (maxb < line_b[i] - memory)
{
maxb = line_b[i] - memory;
//cout << maxb << "\n";
}
memory = line_b[i];
}
cout << maxa * maxb;
}