#include <iostream>

 #include<cstdio>

 #include<cstring>

 #include<algorithm>

 #include<stdlib.h>

 #include<vector>

 #include<cmath>

 #include<queue>

 #include<set>

 using namespace std;

 #define N 510

 #define LL long long

 #define INF 0xfffffff

 const double eps = 1e-;

 const double pi = acos(-1.0);

 const double inf = ~0u>>;

 struct point

 {

     double x,y;

     point(double x=,double y=):x(x),y(y) {} //构造函数 方便代码编写

 }p[N],q[N];

 typedef point pointt;

 pointt operator + (point a,point b)

 {

     return point(a.x+b.x,a.y+b.y);

 }

 pointt operator - (point a,point b)

 {

     return point(a.x-b.x,a.y-b.y);

 }

 int dcmp(double x)

 {

     if(fabs(x)<eps) return ;

     else return x<?-:;

 }

 bool operator == (const point &a,const point &b)

 {

     return dcmp(a.x-b.x)==&&dcmp(a.y-b.y)==;

 }

 double cross(point a,point b)

 {

     return a.x*b.y-a.y*b.x;

 }

 double Polyarea(point p[],int n)

 {

     if(n<) return ;

     double area = ;

     for(int i =  ; i < n ; i++)

     area+=cross(p[i],p[i+]);

     return fabs(area)/;

 }

 //double Polyarea(point p[], int n)

 //{

 //    if(n < 3) return 0.0;

 //    double s = p[0].y * (p[n - 1].x - p[1].x);

 //    p[n] = p[0];

 //    for(int i = 1; i < n; ++ i)

 //        s += p[i].y * (p[i - 1].x - p[i + 1].x);

 //    return fabs(s * 0.5);

 //}

 bool intersection1(point p1, point p2, point p3, point p4, point& p)      // 直线相交

 {

     double a1, b1, c1, a2, b2, c2, d;

     a1 = p1.y - p2.y;

     b1 = p2.x - p1.x;

     c1 = p1.x*p2.y - p2.x*p1.y;

     a2 = p3.y - p4.y;

     b2 = p4.x - p3.x;

     c2 = p3.x*p4.y - p4.x*p3.y;

     d = a1*b2 - a2*b1;

     if (!dcmp(d))    return false;

     p.x = (-c1*b2 + c2*b1) / d;

     p.y = (-a1*c2 + a2*c1) / d;

     return true;

 }

 double convexpolygon(point p[],point q[],int n,int m)

 {

     int i,j;

     point ch[],cnt[];

     p[n] = p[],q[m] = q[];

     memcpy(ch,q,sizeof(point)*(m+));

     int f2,g =  ;

     for(i =  ;i < n; i++)

     {

         int f1 = dcmp(cross(p[i+]-p[i],ch[]-p[i]));

         g =  ;

         for(j =  ;j < m; j++,f1 = f2)

         {

             if(f1>=) cnt[g++] = ch[j];

             f2 = dcmp(cross(p[i+]-p[i],ch[j+]-p[i]));

             if((f1^f2)==-)

             {

                 point pp;

                 intersection1(p[i],p[i+],ch[j],ch[j+],pp);

                 cnt[g++] = pp;

             }

         }

         cnt[g] = cnt[];

         memcpy(ch,cnt,sizeof(point)*(g+));

         m = g;

     }

     return Polyarea(ch,g);

 }

 double solve(point p[],point q[],int n,int m)

 {

     int i,j;

     double area = ;

     point tp[],tq[];

     tp[] = p[];tq[] = q[];

     for(i =  ;i < n-; i++)

     {

         int k1 = dcmp(cross(p[i]-p[],p[i+]-p[]));

         tp[] = p[i],tp[] = p[i+];

         if(k1 < ) swap(tp[],tp[]);

         for(j =  ;j < m- ;j++)

         {

             tq[] = q[j],tq[] = q[j+];

             int k2 = dcmp(cross(q[j]-q[],q[j+]-q[]));

             if(k2<) swap(tq[],tq[]);

             area+=convexpolygon(tp,tq,,)*k1*k2;

         }

     }

     return Polyarea(p,n)+Polyarea(q,m)-area;

 }

 int main()

 {

     int n,m,i;

     while(scanf("%d%d",&n,&m)!=EOF)

     {

         for(i = ; i < n ;i++)

         {

             scanf("%lf%lf",&p[i].x,&p[i].y);

         }

         for(i = ; i < m; i++)

         {

             scanf("%lf%lf",&q[i].x,&q[i].y);

         }

         p[n] = p[],q[m] = q[];

         double ans = solve(p,q,n,m);

         printf("%.2f\n",ans);

     }

     return ;

 }