#include<iostream>
#include<string>
#include<algorithm>
#include<cmath>
#include<iomanip>
#include<cstring>
#include<map>
#include<vector>
#include<queue>
using namespace std;
typedef long long int ll;

int main(){

  double d;
  cin >> d;
  cout << fixed;
  cout << setprecision(2) << d+d*0.08 << endl;
  
  return 0;
}