#include<bits/stdc++.h>
using namespace std;
int main(){
	int n;
	cin>>n;
	if(n<10){
		printf("%.1f",n*1.5);
	}else{
		printf("%.1f",n*1.2);
	}
} 
/**************************************************************
	Problem: 1630
	User: linzihang
	Language: C++
	Result: Accepted
	Time:15 ms
	Memory:2072 kb
****************************************************************/