#include <iostream>
#include <cmath>
#include <iomanip>
using namespace std;
int main(){
    double p1,p2,p3,p4,p5;
    cin >> p1 >> p2 >> p3 >> p4 >> p5;
    double win=p4+p5;
    double lose=1-win;
    double sum=1-pow(lose,10)-10*win*pow(lose,9);
    cout << fixed << setprecision(10) << sum << endl;
}