#include<iostream> #include<cstdio> #include<cmath> #include<algorithm> using namespace std; int main() { int n; double w[105]; while(~scanf("%d",&n)) { for(int i=0;i<n;i++) { int m; scanf("%d",&m); w[i]=m*1.0; } sort(w,w+n); for(int i=n-1;i>0;i--) { w[i-1]=2*sqrt(w[i]*w[i-1]); } printf("%.3lf ",w[0]); } return 0; }