#include <iostream> using namespace std; int main() { int km; double fee; cin >> km; if (km <= 2) { fee = 6; } else if (km <= 10) { fee = 6 + (km - 2) * 1.8; } else { fee = 6 + 8 * 1.8 + (km - 10) * 1.8 * 1.5; } cout << fee << endl; return 0; }