#include <bits/stdc++.h>
#define MOD 998244353
#define mod 1000000007
#define ll long long
#define ii int
using namespace std;
const ii maxn = 1e6+9;
ii n,m,k,x,y,o,p; 
ii main()
{
	cin >> n >> m >> k;
	bool vis[n][n];
	memset(vis,false,sizeof(vis));
	for (int i = 0; i < m; i++)
	{
	    cin >> x >> y;
	    for (int j = y - 2; j <= y + 2; j++) vis[x][j] = true;
	    for (int j = x - 2; j <= x + 2; j++) vis[j][y] = true;
    }
    for (int i = 0; i < k; i++)
    {
        cin >> o >> p;
        for (int j = o - 2; j <= o + 2; j++)
        {
            for (int k = p - 2; k <= p + 2; k++)
                vis[j][k] = true;
        }
    }
    int cnt = 0;
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < n; j++)
        {
            if (!vis[i][j])
                cnt++;
        }
    }
    cout << cnt;
	return 0;
}