#include <fstream>
#include <vector>
#include <complex>
#include <stdio.h>

using namespace std;

typedef complex<int> P;

double getWidth(vector<P> &g, int x){
	double m = 1e10, M = -1e10;
	for(int i=0;i<g.size();i++){
		P a = g[i], b = g[(i+1)%g.size()];
		if(real(a) > real(b)) swap(a, b);
		if(real(a) != real(b) && real(a) <= x && x <= real(b)){
			double mid = (double)(x-real(a))/(real(b)-real(a));
			double d = imag(a)*(1-mid)+imag(b)*mid;
			m = min(d, m);
			M = max(d, M);
		}
	}
	return max(0.0, M-m);
}

int main(){
	int n, m;
	ifstream fin("I.in");
	while(fin >> m >> n, m){
		vector<P> gy(m), gz(n);
		int sy = 100, ey = -100, sz = 100, ez = -100; 
		for(int i=0;i<m;i++){
			fin >> real(gy[i]) >> imag(gy[i]);
			sy = min(sy, real(gy[i]));
			ey = max(ey, real(gy[i]));
		}
		for(int i=0;i<n;i++){
			fin >> real(gz[i]) >> imag(gz[i]);
			sz = min(sz, real(gz[i]));
			ez = max(ez, real(gz[i]));
		}
		double res = 0.0;
		for(int i=max(sy, sz);i+1<=min(ey, ez);i++){
			double py = getWidth(gy, i), cy = getWidth(gy, i+1), pz = getWidth(gz, i), cz = getWidth(gz, i+1);
			res += (cy*cz+(cy+py)*(cz+pz)+py*pz)/6.0;
		}
		printf("%.4lf\n", res);
	}
}