//60//2re求调

#include<bits/stdc++.h>
using namespace std;
int a[101][101];
int main(){
    int n;
    int m;
    int k;
    cin>>n>>m>>k;
    int x,y,o,p;
    for(int i=1;i<=m;i++){
        cin>>x>>y;
        a[x][y]=1;
        a[x+1][y]=1;
        a[x+2][y]=1;
        a[x-2][y]=1;
        a[x-1][y]=1;
        a[x][y-1]=1;
        a[x][y-2]=1;
        a[x][y+1]=1;
        a[x][y+2]=1;
        a[x+1][y+1]=1;
        a[x+1][y-1]=1;
        a[x-1][y-1]=1;
        a[x-1][y+1]=1;
    }
    if(k!=0){
        for(int j=1;j<=k;j++){
            cin>>o>>p;
            for(int h=o-2;h<=o+2;h++){
                for(int h1=p-2;h1<=p+2;h1++){
                    a[h][h1]=1;
                }
            }
        }
    }
    int g=0;
    for(int h0=1;h0<=n;h0++){                
        for(int h10=1;h10<=n;h10++){                    
            //cout<<a[h0][h10]<<" ";
            if(a[h0][h10]==0){
                g++;
            }
        }
        //cout<<endl;
    }
    cout<<g;
	return 0;
}