#include<bits/stdc++.h>
using namespace std;
int main(){
	int x;
	float q;
	cin>>x;
	if(x>=10){
	q=x*2;
	cout<<q; 
	}else{
	q*2.2;
	cout<<q;
	} 
	return 0;
} 
/**************************************************************
	Problem: 1303
	User: fuhoubin
	Language: C++
	Result: Wrong Answer
****************************************************************/