#include <bits/stdc++.h> using namespace std; int main() { int a; double b; cin>>a; 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; }