#include <bits/stdc++.h> using namespace std; int main() { double a1,a2,b1,b2,c1,c2,d1,d2; cin>>a1>>a2>>b1>>b2>>c1>>c2>>d1>>d2; double yi = max(min(a1,b1),min(c1,d1)); double er = max(min(a2,b2),min(c2,d2)); double san = min(max(a1,b1),max(c1,d1)); double si = min(max(a2,b2),max(c2,d2)); if(san > yi && si > er) { cout<<setprecision(2)<<fixed<<(san - yi) * (si - er)<<endl; return 0; } cout<<setprecision(2)<<fixed<<0.00<<endl; return 0; }