#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
#define rep(i,n) for(int i=0;i<(n);i++)

int main(void){
	long long d; cin >> d;
	d *= 108;
	double ans;
	ans = (double)d / 100.0;
	cout << ans << endl;
	return 0;
}