#include<iostream>
#include<iomanip>
using namespace std;
int main(){
    cout << fixed << setprecision(10);
    double a;
    double s[50] ;
    int n = 0;
    while(cin >> a ){
    
        s[n] = a;
        for(int i = 1;i < 10;i++){
           
            if(i % 2 == 0){
                a = a/3;
            }
            else{
                a = a*2;
            }
            s[n] += a;
        }
        
        n++;
    }
    for(int i = 0;i < n;i++){
        cout << s[i] <<endl; 
    }
    
    return 0;
}
