#include<bits/stdc++.h>
using namespace std;
int n;
int main(){
    cin>>n;
    if(n<10) cout<<fixed<<setprecision(1)<<n*1.5;
    else cout<<fixed<<setprecision(1)<<n*1.2;
}
/**************************************************************
	Problem: 1630
	User: panjinyan
	Language: C++
	Result: Accepted
	Time:11 ms
	Memory:2072 kb
****************************************************************/