#include <iostream>
#include <vector>
using namespace std;

int main() {
	vector <double> a;
	double b;
	
	while (cin >> b){
		a.push_back(b);
	}
	double min=a[0]*a[a.size()/2];
	for(int i=0; i<(a.size())/2; i++){
		if (a[i]*a[(a.size()/2+i)]< min){
			min = a[i]*a[(a.size()/2+i)];
		}
	}
	cout << min;

	return 0;
}