#include<bits/stdc++.h>
using namespace std;
int main() {
	float f,q;
	cin>>f;
	if(f>=10){
		q=1.2*f;
	}else{
		q=1.5*f;}
	printf("%.1f",q); 
    return 0;
}

/**************************************************************
	Problem: 1630
	User: huangcanwu
	Language: C++
	Result: Accepted
	Time:22 ms
	Memory:2072 kb
****************************************************************/