#include<bits/stdc++.h>
using namespace std;
bool z[10000][10000];
int main(){
    int n,m,a,x,y,i,j,u,v,ans;
    cin>>n>>m>>a;
    for(i=1;i<=m;i++){
        cin>>x>>y;
        z[x-2][y]=z[x-1][y+1]=z[x-1][y]=z[x-1][y-1]=z[x][y+2]=z[x][y+1]=z[x][y]=z[x][y-1]=z[x][y-2]=z[x+1][y+1]=z[x+1][y]=z[x+1][y-1]=z[x+2][y]=1;
    }
    for(i=1;i<=a;i++){
        cin>>x>>y;
        for(u=-2;u<=2;u++)
            for(v=-2;v<=2;v++)
                z[x+u][y+v]=1;
    }
    for(i=1;i<=n;i++)
        for(j=1;j<=n;j++)
            if(z[i][j]==0)
                ans++;
    cout<<ans;
    return 0;
}