#include <iostream>
#include <iomanip>

using namespace std;

int main() {
    long long int a;
    long long int i;
	double a1;
    cin >> a;
    i = a*108;
    a1 = (double)(i - i/100*100)/100;
	cout << fixed << setprecision(2) << i/100 + a1 << endl;
    return 0;
}