#include<bits/stdc++.h>
using namespace std;
int main(){
	float n;
	cin>>n;
	if(n>30){
		cout<<n*1;
	}if(n>20&&n<29){
		cout<<n*1.2;
	}if(n>10&&n<19){
		cout<<n*1.5;
	}else{
		cout<<1.8;
	}
	printf("%.1f",n);
	return 0;
}
/**************************************************************
	Problem: 1304
	User: chenyaohuo
	Language: C++
	Result: Wrong Answer
****************************************************************/