deepseek神力

#include <iostream>
#include <cmath>
#include <iomanip>
using namespace std;

int main() {
    double L, d;
    cin >> L >> d;
    
    double ans;
    if (L <= d) {
        ans = 0.0;
    } else {
        double ratio = L / d;
        ans = 7.0/9.0 + (2.0/3.0) * log(ratio) + (2.0/9.0) * pow(1.0/ratio, 3.0);
    }
    
    cout << fixed << setprecision(6) << ans << endl;
    return 0;
}