测试的时候是0

#include<bits/stdc++.h>
using namespace std;int a,b[10000][10000],c,d,e,f,g;
int main() {
cin>>a>>c>>d;
for(int i=1;i<=a;i++){
	for(int j=1;j<=a;j++)
	b[i][j]=1;
}
for(int i=1;i<=c;i++){
	cin>>e>>f;
	b[e][f]=2;
	b[e][f-1]=1;
	b[e-1][f]=1;
	b[e][f+1]=1;
	b[e+1][f]=1;
	b[e-1][f-1]=1;
	b[e-1][f+1]=1;
	b[e+1][f-1]=1;
	b[e+1][f+1]=1;
	b[e-2][f]=1;
	b[e+2][f]=1;
	b[e][f+2]=1;
	b[e][f-2]=1;
}
for(int i=1;i<=d;i++){
	cin>>e>>f;
	b[e][f]=3;
	for(int i=c-2;i<=c+2;i++){
		for(int j=d-2;j<=d+2;j++){
			b[i][j]=1;
		}
	}
}
for(int i=1;i<=a;i++){
	for(int j=1;j<=a;j++){
		if(b[i][j]==0){
			g++;
		}
	}
}
cout<<g;
}