#include <bits/stdc++.h>

using namespace std;

#define SZ(x) (int)(x.size())
#define REP(i, n) for(int i=0;i<n;++i)
#define FOR(i, a, b) for(int i=a;i<b;++i)
#define RREP(i, n) for(int i=n-1;i>=0;--i)
#define RFOR(i, a, b) for(int i=b-1;i>=a;--i)
#define ALL(a) a.begin(),a.end()
#define DUMP(x) cerr<<#x<<" = "<<(x)<<endl
#define DEBUG(x) cerr<<#x<<" = "<<(x)<<" (L"<<__LINE__<<")"<< endl;

using ll = long long;
using ld = double;
#define double ld
using vi = vector<int>;
using vvi = vector<vi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using P = pair<int, int>;

const double eps = 1e-8;
const double EPS = eps;
const ll MOD = 1000000007;
const int INF = INT_MAX / 2;
const ll LINF = LLONG_MAX / 2;

template <typename T1, typename T2>
bool chmax(T1 &a, const T2 &b) {
  if(a < b) {a = b; return true;}
  return false;
}

template <typename T1, typename T2>
bool chmin(T1 &a, const T2 &b) {
  if(a > b) {a = b; return true;}
  return false;
}

template<typename T>
void printv(const vector<T>& s) {
  for(int i=0;i<(int)(s.size());++i) {
    cout << s[i];
    if(i != (int)(s.size())-1) cout << " ";
  }
  cout << "\n";
}

template<class T>
ostream &operator<<(ostream &os, const vector<T> &v) {
  os << "[";
  REP(i, SZ(v)) {
    if(i) os << ", ";
    os << v[i];
  }
  return os << "]";
}

template<typename T1, typename T2>
ostream& operator<<(ostream &os, const pair<T1, T2> p) {
  os << p.first << ":" << p.second;
  return os;
}

using Real = double;
const Real PI = acos(-1);

using Point = complex<Real>;
namespace std {
  bool operator<(const Point& a, const Point& b) {
    if (a.real() == b.real()) return a.imag() < b.imag();
    return a.real() < b.real();
  }
}
struct Line {
  Point a, b;
  Line() {}
  Line(const Point& a, const Point& b) : a(a), b(b) {}
  friend ostream& operator<<(ostream& os, const Line& l) {
    return os << "[" << l.a << "," << l.b << "]";
  }
};
struct Segment : Line {
  Segment() = default;

  Segment(const Point& a, const Point& b) : Line(a, b) {}
};

inline bool eq(Real a, Real b) { return abs(b - a) < EPS; }

Real radian_to_degree(Real r) {
  return r * 180.0 / PI;
}

Real degree_to_radian(Real d) {
  return d * PI / 180.0;
}

Point rotate(const Point &p, Real theta) {
  return p * polar((Real)1.0, theta);
}

Real cross(const Point& a, const Point& b) {
  return a.real() * b.imag() - a.imag() * b.real();
}

Real dot(const Point& a, const Point& b) {
  return a.real() * b.real() + a.imag() * b.imag();
}

Point projection(const Line& l, const Point& p) {
  Real A = dot(l.b - l.a, p - l.a),
          B = dot(l.a - l.b, p - l.b);
  return (A * l.b + B * l.a) / (A + B);
}

bool parallel(const Line& l1, const Line& l2) {
  return eq(cross(l1.a - l1.b, l2.a - l2.b), 0.0);
}

bool orthogonal(const Line& l1, const Line& l2) {
  return eq(dot(l1.a - l1.b, l2.a - l2.b), 0.0);
}

const int COUNTER_CLOCKWISE = 1,
        CLOCKWISE = -1,
        ONLINE_BACK = 2,
        ONLINE_FRONT = -2,
        ON_SEGMENT = 0;
int ccw(const Point& a, Point b, Point c) {
  b = b - a, c = c - a;
  if (cross(b, c) > EPS) return COUNTER_CLOCKWISE;
  if (cross(b, c) < -EPS) return CLOCKWISE;
  if (dot(b, c) < 0) return ONLINE_BACK;
  if (norm(b) < norm(c)) return ONLINE_FRONT;
  return ON_SEGMENT;
}

bool intersected(const Line& l, const Point& p) {
  return abs(ccw(l.a, l.b, p)) != 1;
}

bool intersected(const Segment& s, const Point& p) {
  return ccw(s.a, s.b, p) == 0;
}

bool intersected(const Line& l, const Segment& s) {
  return cross(l.b - l.a, s.a - l.a) * cross(l.b - l.a, s.b - l.a) < EPS;
}

bool intersected(const Segment& s1, const Segment& s2) {
  return ccw(s1.a, s1.b, s2.a) * ccw(s1.a, s1.b, s2.b) <= 0 and
         ccw(s2.a, s2.b, s1.a) * ccw(s2.a, s2.b, s1.b) <= 0;
}

Real distance(const Line& l, const Point& p) {
  return abs(p - projection(l, p));
}

Real distance(const Segment& s, const Point& p) {
  Point r = projection(s, p);
  if (intersected(s, r)) return abs(r - p);
  return min(abs(s.a - p), abs(s.b - p));
}

Real distance(const Line &l, const Segment &s) {
  if (intersected(l, s)) return 0;
  return min(distance(l, s.a), distance(l, s.b));
}

Real distance(const Segment& s1, const Segment& s2) {
  if (intersected(s1, s2)) return 0.0;
  return min({ distance(s1, s2.a), distance(s1, s2.b),
               distance(s2, s1.a), distance(s2, s1.b) });
}

Point crosspoint(const Line& l1, const Line& l2) {
  Real A = cross(l2.a - l1.a, l2.b - l1.a),
          B = cross(l2.b - l1.b, l2.a - l1.b);
  return (A * l1.b + B * l1.a) / (A + B);
}

struct Circle {
  Point p;
  Real r;
  Circle() {}
  Circle(const Point& p, Real r) : p(p), r(r) {}
};


int intersected(Circle c1, Circle c2) {
  if (c1.r < c2.r) swap(c1, c2);
  Real d = abs(c1.p - c2.p);
  if (c1.r + c2.r < d) return 4;
  if (eq(c1.r + c2.r, d)) return 3;
  if (c1.r - c2.r < d) return 2;
  if (eq(c1.r - c2.r, d)) return 1;
  return 0;
}

pair<Point,Point> crosspoint(const Circle& c, const Line& l) {
  Real h = distance(l, c.p);
  Point p = projection(l, c.p);
  if (eq(h, c.r)) return { p, p };
  Point u = l.a - l.b; u /= abs(u);
  Real d = sqrt(c.r * c.r - h * h);
  return { p + u * d, p - u * d };
}

pair<Point,Point> crosspoint(const Circle& c1, const Circle& c2) {
  Real d = abs(c2.p - c1.p), t = arg(c2.p - c1.p);
  Real a = acos((c1.r * c1.r + d * d - c2.r * c2.r) / (2 * c1.r * d));
  return { c1.p + polar(c1.r, t + a),
           c1.p + polar(c1.r, t - a) };
}

pair<Point,Point> tangent(const Point& p, const Circle& c) {
  return crosspoint(c, Circle(p, sqrt(norm(p - c.p) - c.r * c.r)));
};

vector<Line> common_tangent(const Circle& c1, const Circle& c2) {
  vector<Line> lines;
  Point u = c2.p - c1.p;
  Real d = abs(u);
  if (eq(d, 0.0)) return lines;
  u /= d;
  for (Real s : { -1, 1 }) {
    Real h = (c1.r + s * c2.r) / d;
    if (eq(abs(h), 1.0)) {
      lines.emplace_back(
              c1.p + u * h * c1.r,
              c1.p + u * h * c1.r + rotate(u, PI / 2.0));
    } else if (abs(h) < 1) {
      Real a = acos(h);
      lines.emplace_back(
              c1.p + u * polar(c1.r, a),
              c2.p - s * u * polar(c2.r, a));
      lines.emplace_back(
              c1.p + u * polar(c1.r, -a),
              c2.p - s * u * polar(c2.r, -a));
    }
  }
  return lines;
}

double width(const vector<Point> &p, double x) {
  int sz = SZ(p);
  double mi = INF, ma = -INF;
  REP(i, sz) {
    double x1 = p[i].real(), x2 = p[(i+1)%sz].real();
    double y1 = p[i].imag(), y2 = p[(i+1)%sz].imag();

    if((x1 - x) * (x2 - x) <= 0 && x1 != x2) {
      double tmp = y1 + (y2 - y1) / (x2 - x1) * (x - x1);
      chmin(mi, tmp);
      chmax(ma, tmp);
    }
  }

  return max(0.0, ma - mi);
}

bool solve() {
  int m, n; cin >> m >> n;
  if(m == 0 && n == 0) return false;

  vector<Point> p1(m), p2(n);
  vector<int> vx;

  int mi1 = INF, ma1 = -INF;
  REP(i, m) {
    int x, y; cin >> x >> y;
    p1[i] = Point(x, y);
    vx.push_back(x);
    chmin(mi1, x);
    chmax(ma1, x);
  }

  int mi2 = INF, ma2 = -INF;
  REP(i, n) {
    int x, z; cin >> x >> z;
    p2[i] = Point(x, z);
    vx.push_back(x);
    chmin(mi2, x);
    chmax(ma2, x);
  }

  sort(ALL(vx));

  vector<double> area(n+m);
  REP(i, n+m) {
    area[i] = width(p1, vx[i]) * width(p2, vx[i]);
  }

  double ans = 0.0;
  REP(i, n+m-1) {
    double dist = vx[i+1] - vx[i];
    double b = (vx[i] + vx[i+1]) / 2.0;
    if(!(mi1 <= b && b <= ma1 && mi2 <= b && b <= ma2)) continue;
    double s = width(p1, b) * width(p2, b);

    //if(abs(area[i] - area[i+1]) < eps) ans += area[i] * dist;
    //else ans += dist / 3.0 * (area[i] + area[i+1] + sqrt(area[i]) * sqrt(area[i+1]));
    ans += dist / 6 * (area[i] + 4 * s + area[i+1]);
  }
  cout << ans << endl;

  return true;
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(10);

  while(1) {
    if(!solve()) break;
  }

}


Measured memory_bytes: 3296