#include<bits/stdc++.h> using namespace std; int main() { int a; cin >> a; double b = 0; if (a <= 2) { b = 6; } else { if (a <= 10) { b = (a - 2) * 1.8 + 6; } else { b=(a-10)*2.7+6+1.8*8; } } cout<<b; return 0; }