#include <iostream>
using namespace std;
int a[105][105];
int n, m, k, x, y, o, p, sum;

int main(){
	cin >> n >> m >> k;
	for(int i = 1;i <= m;i++){
		cin >> x >> y;
		a[x][y] = 1;
		a[x - 2][y] = 1;
		a[x - 1][y] = 1;
		a[x - 1][y - 1] = 1;
		a[x - 1][y + 1] = 1;
		a[x][y - 2] = 1;
		a[x][y - 1] = 1;
		a[x][y + 1] = 1;
		a[x][y + 2] = 1;
		a[x + 1][y] = 1;
		a[x + 1][y - 1] = 1;
		a[x + 1][y + 1] = 1;
		a[x + 2][y] = 1;
	}
	for(int i = 1;i <= k;i++){
		cin >> o >> p;
		for(int j = o - 2;j <= o + 2;j++){
			for(int k = p - 2;k <= p + 2;k++){
				a[j][k] = 1;
			}
		}
	}
	for(int i = 1;i <= n;i++){
		for(int j = 1;j <= n;j++){
			if(a[i][j] == 0){
				sum++;
			}
		}
	}
	cout << sum;
	return 0;
}

如何让数组不变得太小（解决RE）?