#include<bits/stdc++.h> using namespace std; int main(){ double x1,y1,x2,y2; double x3,y3,x4,y4; double m1,n1; //交集左上角坐标. double m2,n2; //交集右下角坐标. cin>>x1>>y1>>x2>>y2; cin>>x3>>y3>>x4>>y4; m1 = max(min(x1,x2),min(x3,x4)); n1 = max(min(y1,y2),min(y3,y4)); m2 = min(max(x1,x2),max(x3,x4)); n2 = min(max(y1,y2),max(y3,y4)); cout<<fixed<<setprecision(2); if(m2>m1 && n2>n1) cout<<(m2 - m1)*(n2 - n1); else cout<<0.0; return 0; }