#include<bits/stdc++.h>
using namespace std;
int main()
{
	int n;
    cin>>n;
    float s;
    if (a>=10){
    	s=n*2.0;
    }
    else {
    	s=n*2.2;
    }
    printf("%.1f",s);
return 0;
}

/**************************************************************
	Problem: 1303
	User: chenzelin
	Language: C++
	Result: Compile Error
****************************************************************/