# include<iostream> # include<cstdio> using namespace std; int main(){ double a,b; cin>>a; if(a<=2){ b=6; } else { if(a<=10){ b=6+(a-2)*1.8; } else{ b=6+8*1.8+(a-2-8)*1.5*1.8; } } cout<<b; return 0; }