#include<iostream> using namespace std; int main() { int n; cin >> n; if (n <= 2) { cout << 6; } if (2 < n && n <= 10) { cout << (n - 2) * 1.8 + 6; } if (n > 10) { cout << 6 + 8 * 1.8 + (n - 10) * 2.7; } }