#include<iostream>
#include<algorithm>
#include<vector>
#include<set>
#include<string>
#include<sstream>
#include<cctype>
#include<functional>
#include<iomanip>
using namespace std;

int main()
{
	double a;
	cin >> a;
	cout << fixed << setprecision(2) << a + a*0.08 << endl;
	return 0;
}