#include <iostream>
#include <string>
#include <vector>
#include <cmath>
#include <algorithm>
#include <cstdlib>
#include <ctime>
#include <cstdio>
#include <functional>
#include <set>
#include <sstream>
#include <map>
#include <queue>
#include <stack>

using namespace std;

int main()
{

    long double n;
    cin>>n;
    n*=108;
    n/=100;

    printf("%.20Lf\n",n);

    return 0;
}