mogi2016c.cpp

#include <algorithm>
#include <cmath>
#include <climits>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <fstream>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
#include <cassert>
#include <functional>

using namespace std;

#define LOG(...) printf(__VA_ARGS__)
//#define LOG(...)
#define FOR(i,a,b) for(int i=(int)(a);i<(int)(b);++i)
#define REP(i,n) for(int i=0;i<(int)(n);++i)
#define ALL(a) (a).begin(),(a).end()
#define RALL(a) (a).rbegin(),(a).rend()
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())
#define RSORT(c) sort((c).rbegin(),(c).rend())
#define CLR(a) memset((a), 0 ,sizeof(a))

typedef long long ll;
typedef unsigned long long ull;
typedef vector<bool> vb;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<vb> vvb;
typedef vector<vi> vvi;
typedef vector<vll> vvll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int dx[] = { -1, 0, 1, 0 }; const int dy[] = { 0, 1, 0, -1 };

int main() {
	int n;
	while (cin >> n, n) {
		vector<pair<long long, long long>> zahyo(n);
		vector<ll> x;
		vector<ll> y;
		REP(i, n) {
			cin >> zahyo[i].second >> zahyo[i].first;
			x.push_back(zahyo[i].second);
			y.push_back(zahyo[i].first);
		}
		vector<pair<long long, long long>> curtain(4);
		REP(i, 4) {
			cin >> curtain[i].second >> curtain[i].first;
			x.push_back(curtain[i].second);
			y.push_back(curtain[i].first);
		}
		SORT(x);
		SORT(y);
		x.erase(unique(x.begin(), x.end()), x.end());
		y.erase(unique(y.begin(), y.end()), y.end());
		
		map<ll, int> zipx;
		map<ll, int> zipy;
		REP(i, x.size())
			zipx[x[i]] = i;
		REP(i, y.size())
			zipy[y[i]] = i;
		vvb tate(y.size()-1,vb(x.size()));
		REP(i, n) {
			int sy = zipy[zahyo[(i + 1) % n].first] - zipy[zahyo[i].first];
			int sx = zipx[zahyo[(i + 1) % n].second] - zipx[zahyo[i].second];
			if (sx == 0) {
				REP(j, abs(sy)) {
					tate[min(zipy[zahyo[(i + 1) % n].first], zipy[zahyo[i].first]) + j][zipx[zahyo[(i + 1) % n].second]] = true;
				}
			}
		}
		int minx = 400;
		int miny = 400;
		int maxx = -400;
		int maxy = -400;
		REP(i, 4) {
			minx = min(minx, zipx[curtain[i].second]);
			miny = min(miny, zipy[curtain[i].first]);
			maxx = max(maxx, zipx[curtain[i].second]);
			maxy = max(maxy, zipy[curtain[i].first]);
		}
		long long ans = 0;
		REP(i, y.size()-1) {
			bool exbox = false;
			int idx = 0;
			REP(j, x.size()-1) {
				if (tate[i][j]) {
					exbox = !exbox;
					idx++;
				}
				if (exbox && !(miny <= i&&i < maxy&&minx <= j&&j < maxx))
					ans += (x[j + 1] - x[j])*(y[i + 1] - y[i]);
			}
		}
		cout << ans << endl;
	}
}