#include<iostream> using namespace std; int main(){ double b,c,d; int a; d=1.8+1.8*0.5; cin>>a; if(a<=2){ cout<<6; } if(a>2 && a<=10){ b=a-2; cout<<6+b*1.8; } if(a>10){ c=a-10; cout<<6+8*1.8+c*d; } }