#include<iostream> using namespace std; int main(){ double a,d,s,f,g; cin>>a; if(a>2){ if(a>10){ s=1.8+1.8*0.5; d=10-2; f=d*1.8; d=a-10; g=s*d; cout<<6+f+g; } else{ d=a-2; f=d*1.8; cout<<6+f; } } else{ cout<<"6"; } }