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