#include<stdio.h>
int ma[1000][1000];
int n,m,x,l,p,y,k,ans=0;
int main()
{
	
	scanf("%d %d %d",&n,&m,&k);
	
	for(int o=1;o<=m;o++)
	{
		scanf("%d %d",&x,&y);
		ma[x-2][y]=ma[x-1][y+1]=ma[x-1][y]=ma[x-1][y-1]=ma[x][y+2]=ma[x][y+1]=ma[x][y]=ma[x][y-1]=ma[x][y-2]=ma[x+1][y+1]=ma[x+1][y]=ma[x+1][y-1]=ma[x+2][y]=1;
	}
	for(int i=1;i<=k;i++){
        scanf("%d %d", &x, &y);
        for(int u=-2;u<=2;u++)
            for(int v=-2;v<=2;v++)
                ma[x+u][y+v]=1;
    }
	for(int i=1;i<=n;i++)
        for(int j=1;j<=n;j++)
            if(ma[i][j]==0)
                ans++;
		printf("%d",ans);
		return 0;
	
	}