#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<ctime>
#include<vector>
#include<queue>
#include<algorithm>
#include<string>
#include<sstream>
#include<cctype>
#include<cmath>
#include<iomanip>
#include<map>
#include<stack>
#include<set>
#include<functional>
#define in(x) x=read()
#define qr read()
#define int ll
#define mp make_pair
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
namespace fastIO
{
    #define BUF_SIZE 100000
    bool IOerror=0;
    inline char nc()
	{
        static char buf[BUF_SIZE],*p1=buf+BUF_SIZE,*pend=buf+BUF_SIZE;
        if (p1==pend){
            p1=buf; pend=buf+fread(buf,1,BUF_SIZE,stdin);
            if (pend==p1){IOerror=1;return -1;}
        }
        return *p1++;
    }
    inline bool blank(char ch){return ch==' '||ch=='\n'||ch=='\r'||ch=='\t';}
    inline ll read()
	{
        bool sign=0; char ch=nc();ll x=0;
        for (;blank(ch);ch=nc());
        if (IOerror)return 0;
        if (ch=='-')sign=1,ch=nc();
        for (;ch>='0'&&ch<='9';ch=nc())x=x*10+ch-'0';
        if (sign)x=-x;
        return x;
    }
    #undef BUF_SIZE
};
using namespace fastIO;
#define x1 x[1]
#define x2 x[2]
#define x3 x[3]
#define x4 x[4]
#define y1 y[1]
#define y2 y[2]
#define y3 y[3]
#define y4 y[4]
#define z1 z[1]
#define z2 z[2]
#define z3 z[3]
#define z4 z[4]
int x[5],y[5],z[5];
struct node
{
	double a,b,c,p;
	int f;
}t[10];
bool cmp(const node& a,const node& b){return a.p<b.p;}
double calc(double a,double b,double c,double x)
{
	return a*x*x*x+b*x*x+c*x;
}
signed main()
{
	//freopen(".in","r",stdin);
	//freopen(".out","w",stdout);
	while(scanf("%lld%lld%lld",&x[1],&y[1],&z[1])!=EOF)
	{
		// scanf("%lld%lld",&y[1],&z[1]);
		// y[1]=qr,z[1]=qr;
		for(int i=2;i<=4;i++)
		scanf("%lld%lld%lld",&x[i],&y[i],&z[i]);//in(x[i]),in(y[i]),in(z[i]);
		// cout<<x1<<' '<<x2<<' '<<x3<<",,,,"<<x4<<'\n';
		if(x1>x2)x1*=-1,x2*=-1,x3*=-1,x4*=-1;
		if(y1>y2)y1*=-1,y2*=-1,y3*=-1,y4*=-1;
		if(z1<z2)z1*=-1,z2*=-1,z3*=-1,z4*=-1;
		if(x3>x4)swap(x3,x4);
		if(y3>y4)swap(y3,y4);
		if(z3>z4)swap(z3,z4);
		if(x1>=x4||y1>=y4)
		{
			puts("0");
			continue;
		}
		int nx=x4-x3,ny=y4-y3;
		int num=0;
		int lx=x4-x1,ly=y4-y1,dx=x3-x1,dy=y3-y1;
		double kx=1.0*(x2-x1)/(z1-z2),ky=1.0*(y2-y1)/(z1-z2);
		// cout<<x1<<' '<<x2<<' '<<x3<<",,,,"<<x4<<'\n';
		// cout<<y1<<' '<<y2<<' '<<y3<<",,,,"<<y4<<'\n';
		// cout<<kx<<",,,,,,,,"<<ky<<'\n';
		int ff=0;
		if(x1>=x3)
		{
			if(y1>=y3)
			{
				double t1=1.0*(x4-x1)/(x2-x1)*(z1-z2)+z2;
				double t2=1.0*(y4-y1)/(y2-y1)*(z1-z2)+z2;
				double t3=1.0*(y4-y1)/(y2-y1)*(z1-z2)+1.0*(x4-x1)/(x2-x1)*(z1-z2)+z2;
				double p=kx*ky/2;
				t[1].a=p,t[1].b=t[1].c=0,t[1].p=z2;
				if(t1<=t2)
				{
					t[2].a=0,t[2].b=ky*lx,t[2].c=-ky*lx*lx/kx/2,t[2].p=t1;
					t[3].a=-kx*ky/2,t[3].b=(kx*(ly+ky/kx*lx)+ky*(lx+kx/ky*ly))/2,t[3].c=lx*ly-(ly+ky/kx*lx)*(lx+kx/ky*ly)/2,t[3].p=t2;
				}
				else
				{
					t[2].a=0,t[2].b=kx*ly,t[2].c=-kx*ly*ly/ky/2,t[2].p=t2;
					t[3].a=-kx*ky/2,t[3].b=(kx*(ly+ky/kx*lx)+ky*(lx+kx/ky*ly))/2,t[3].c=lx*ly-(ly+ky/kx*lx)*(lx+kx/ky*ly)/2,t[3].p=t1;
				}
				t[4].a=t[4].b=0,t[4].c=lx*ly,t[4].p=t3;
				t[1].f=t[2].f=t[3].f=t[4].f=1;
			}
			else
			{
				double t1=dy/ky+z2;
				double t3=ly/ky+z2;
				double t2=lx/kx+dy/ky+z2;
				double t4=lx/kx+ly/ky+z2;
				t[1].a=kx*ky/2,t[1].b=-dy*kx,t[1].c=kx*dy*dy/ky/2,t[1].p=t1;
				if(t3<=t2)
				{
					t[2].a=0,t[2].b=kx*ny,t[2].c=-(kx*ny*(ly+dy))/(2*ky),t[2].p=t3;
					t[3].p=t2;
				}
				else
				{
					t[2].a=0,t[2].b=ky*lx,t[2].c=-lx*lx*ky/kx/2-dy*lx,t[2].p=t2;
					t[3].p=t3;
				}
				t[3].a=-kx*ky/2,t[3].b=kx*ly+ky*lx,t[3].c=ny*lx-(ly+ky/kx*lx)*(lx+kx/ky*ly)/2;
				t[4].a=t[4].b=0,t[4].c=lx*ny,t[4].p=t4;
				t[1].f=t[2].f=t[3].f=t[4].f=1;
			}
		}
		else
		{
			if(y1>=y3)
			{
				double t1=dx/kx+z2;
				double t3=lx/kx+z2;
				double t2=ly/ky+dx/kx+z2;
				double t4=lx/kx+ly/ky+z2;
				t[1].a=kx*ky/2,t[1].b=-dx*ky,t[1].c=ky*dx*dx/kx/2,t[1].p=t1;
				if(t3<=t2)
				{
					t[2].a=0,t[2].b=ky*nx,t[2].c=-(ky*nx*(lx+dx))/(2*kx),t[2].p=t3;
					t[3].p=t2;
				}
				else
				{
					t[2].a=0,t[2].b=kx*ly,t[2].c=-ly*ly*kx/ky/2-dx*ly,t[2].p=t2;
					t[3].p=t3;
				}
				t[3].a=-kx*ky/2,t[3].b=ky*lx+kx*ly,t[3].c=nx*ly-(lx+kx/ky*ly)*(ly+ky/kx*lx)/2;
				t[4].a=t[4].b=0,t[4].c=ly*nx,t[4].p=t4;
				t[1].f=t[2].f=t[3].f=t[4].f=1;
			}
			else
			{
				double t1=dx/kx+dy/ky+z2;
				double t2=lx/kx+dy/ky+z2;
				double t3=dx/kx+ly/ky+z2;
				double t4=lx/kx+ly/ky+z2;
				t[1].a=kx*ky/2,t[1].b=-dx*ky-dy*kx,t[1].c=(dx+dy*kx/ky)*(dy+dx*ky/kx)/2,t[1].p=t1;
				if(t2<=t3)
				{
					t[2].a=0,t[2].b=nx*ky,t[2].c=-nx*dy-nx*(dx+lx)*ky/(2*kx);
					t[2].p=t2,t[3].p=t3;
				}
				else
				{
					t[2].a=0,t[2].b=ny*kx,t[2].c=-ny*dx-ny*(dy+ly)*kx/(2*ky);
					t[2].p=t3,t[3].p=t2;
				}
				t[3].a=-kx*ky/2,t[3].b=(kx*ly+lx*ky),t[3].c=nx*ny-(lx+ly*kx/ky)*(ly+lx*ky/kx)/2;
				t[4].a=t[4].b=0,t[4].c=ny*nx,t[4].p=t4;
				t[1].f=t[2].f=t[3].f=t[4].f=1;
			}
		}
		t[5].p=z3,t[5].f=2;
		t[6].p=z4,t[6].f=-1;
		t[7].p=z1,t[7].f=-1;
		sort(t+1,t+8,cmp);
		int f=0,g=0;
		double na=0,nb=0,nc=0,pre,ans=0;
		for(int i=1;i<=7;i++)
		{
			if(t[i].f==2)f=1;
			else if(t[i].f==-1)
			{
				if(f&&!g)
				{
					// if(calc(na/3,nb/2,nc,t[i].p-z2)<calc(na/3,nb/2,nc,pre-z2))printf("%lld,%lld,%lld,%lld,%lld,%lld,%lld,%lld,%lld,%lld,%lld,%lld\n",x1,x2,x3,x4,y1,y2,y3,y4,z1,z2,z3,z4);
					ans+=calc(na/3,nb/2,nc,t[i].p-z2)-calc(na/3,nb/2,nc,pre-z2);
				}
				g=1;
			}
			else
			{
				if(f&&!g)
				{
					// if(calc(na/3,nb/2,nc,t[i].p-z2)<calc(na/3,nb/2,nc,pre-z2))cout<<"i2="<<i<<'\n';
					ans+=calc(na/3,nb/2,nc,t[i].p-z2)-calc(na/3,nb/2,nc,pre-z2);
				}
				na=t[i].a,nb=t[i].b,nc=t[i].c;
			}
			pre=t[i].p;
		}
		// if(ans<0)cout<<num<<'\n';
		printf("%.8f\n",ans);
	}
	return 0;
}