include[HTML_REMOVED]
include[HTML_REMOVED]
include[HTML_REMOVED]
include[HTML_REMOVED]
include[HTML_REMOVED]
include[HTML_REMOVED]
using namespace std;
typedef unsigned long long ll;
const int N = 1e5+10;
bool a[N];
bool b[N];
int main()
{
int n, m, q;
cin >> n >> m >> q;
ll sum=0;
memset(a,false,sizeof(a));
memset(b,false,sizeof(b));
for (int i = 1; i <= q; i)
{
int c,d;
cin >> c >> d;
if(c==0)
{
a[d]=true;
}
else
{
b[d]=true;
}
}
for(int i=1;i<=n;i)
{
for(int j=1;j<=m;j)
{
if(!a[i]&&!b[j])
{
sum;
}
}
}
cout << sum;
return 0;
}