#include<iostream> using namespace std; int main(){ int a = 2,b = 6,c = 10,f; float d = 1.8,e = 2.7; cin>>f; if(f <= a){ cout<<b; }else if(f <= c){ cout<<b+(f-a)*d; }else{ cout<<b+8*d+(f-10)*e; } return 0; }