#include <bits/stdc++.h> #include using namespace std;

int main() { double weight; cin >> weight; double cost; // 判断行李重量是否小于等于 20 公斤 if (weight <= 20) { cost = weight * 1.68; } else { cost = weight * 1.98; } // 输出费用，保留两位小数 cout << fixed << setprecision(2) << cost << endl; return 0; }