#include<bits/stdc++.h> using namespace std; int main(){ int a; double b,c,d,e,f; c =0; d = 0; b = 6; e = 0; f = 0; cin>>a; if(a<=2){ cout<<6; } if(a>2&&a<=10){ c = (a-2)*1.8; b = b+c; cout<<b; } if(a>10){ d = 1.8*1.5; e = (a-10)*d+(a-10-2)*1.8; f = b+e; cout<<f; } return 0; }