int arr[1100][1100]={0};

int main( )
{
	int n,m,k;
	cin>>n>>m>>k;
	for(int i=1;i<=m;i++)
	{
		int x,y;
		cin>>x>>y;
		x+=2;
		y+=2;
		arr[x-2][y]++;
		arr[x-1][y]++;
		arr[x-1][y-1]++;
		arr[x-1][y+1]++;
		arr[x][y-2]++;
		arr[x][y-1]++;
		arr[x][y]++;
		arr[x][y+1]++;
		arr[x][y+2]++;
		arr[x+1][y-1]++;
		arr[x+1][y]++;
		arr[x+1][y+1]++;
		arr[x+2][y]++;
	}
	for(int i=1;i<=k;i++)
	{
		int x,y;
		cin>>x>>y;
		x+=2;
		y+=2;
		for(int i=x-2;x<=x+2;x++)
		{
			for(int j=y-2;y<=y+2;y++)
			{
				arr[i][j]=1;
			}
		}
	}
	int ans=0;
	for(int i=3;i<=n+2;i++)
	{
		for(int j=3;j<=n+2;j++)
		{
			if(arr[i][j]==0)
			{
				ans++;
			}
		}
	}
	cout<<ans;
	
	return 0;
}