#include <bits/stdc++.h> using namespace std; int main (){ double a,b,c,d,x; double j; scanf("%lf%lf%lf%lf%lf",&a,&b,&c,&d,&x); double as = x*x; double s = as*x; j = a*s+b*as+c*x+d; printf("%.5lf",j);