#include <iostream>
#include <vector>
#include <list>
#include <algorithm>
#include <string>
#include <stack>
#include <iomanip>
#include <numeric>
#include <queue>
#include <climits>
#include <complex>
#include <cmath>
#include <map>
using namespace std;
using ll = long long;
#define MOD 1000000007
#define INF 1LL << 59

int main()
{
    std::ios::sync_with_stdio(false);
    std::cin.tie(0);
    cout << fixed << setprecision(7);

    double n;
    while (scanf("%lf", &n) != EOF)
    {
        double sum = n;
        for (int i = 2; i <= 10; ++i)
        {
            if (i % 2 == 0)
            {
                n *= 2.0;
            }
            else
            {
                n /= 3.0;
            }
            sum += n;
        }
        cout << sum << endl;
    }
    return 0;
}
