#include <iostream>
using namespace std;
int main(){
  double n,ans;
  cin >> n;
    ans = n;
    for(int i = 2 ; i <= 10 ; i++){
      if(i%2 == 1){
	n = n/3;
	ans += n;
      }
      else{
	n*=2;
	ans +=n;
      }
    }
    cout << ans << endl;

}