#include <iostream>
#include <vector>
#include <cstdio>
#include <sstream>
#include <map>
#include <string>
#include <algorithm>
#include <queue>
#include <cmath>
#include <set>
using namespace std;

int main(){
	long long d;
	cin >> d;
	long long ans;
	ans = d*100 + d*8;

	char hoge[100];
	sprintf(hoge,"%lld", ans);

	string hage(hoge);
	cout << hage.substr(0, hage.size()-2) << "." << hage.substr(hage.size()-2) << endl;
	return 0;
}