#include<stdio.h>
int main()
{
	int n, m, k, a[104][104] = {};
	scanf_s("%d %d %d", &n, &m, &k);
	int x, y, i, j, p, q, cnt = 0;
	for (i = 2; i <= m + 1; i++)
	{
		scanf("%d %d", &x, &y);
		x = x + 2;
		y = y + 2;
		for (p = x - 1; p <= x + 1; p++)
			for (q = y - 1; q <= y + 1; q++) a[p][q] = 1;
		a[x - 2][y] = 1; a[x + 2][y] = 1; a[x][y - 2] = 1; a[x][y + 2] = 1;
	}
	if (k > 0)
	{
		for (i = m + 2; i <= m + k + 1; i++)
		{
			scanf("%d %d", &x, &y);
			x = x + 2;
			y = y + 2;
			for (p = x - 2; p <= x + 2; p++)
				for (q = y - 2; q <= y + 2; q++) a[p][q] = 1;
		}
	}
	for (i = 2; i <= n + 1; i++)
		for (j = 2; j <= n + 1; j++)
			if (a[i][j] != 1) cnt++;
	printf("%d", cnt);
	return 0;
}