#include <iostream>
#include <math.h>

using namespace std;

class GoldenRatio {

private:
    static const double phi() {
        return (1 + sqrt(5)) / 2;
    }

public:
    double static f(double x) {
        return pow(x + 1, 3) + 5 * pow(x, 2);
    }

    double static min(double a, double b, double e){
        double x1, x2, delta;
        while (abs(b - a) > e){
            delta = (b - a) / phi();
            x1 = b - delta;
            x2 = a + delta;
            if (f(x1) >= f(x2)) {
                a = x1;
            } else {
                b = x2;
            }
        }
        return (a + b) / 2;
    }

    double static max(double a, double b, double e){
        double x1, x2, delta;
        while (abs(b - a) > e){
            delta = (b - a) / phi();
            x1 = b - delta;
            x2 = a + delta;
            if (f(x1) <= f(x2)) {
                a = x1;
            } else {
                b = x2;
            }
        }
        return (a + b) / 2;
    }
};

int main() {
    double a, b, e;
    int select = 0;
    cout << "Enter a:";
    cin >> a;
    cout << "Enter b:";
    cin >> b;
    cout << "Enter epsilon:";
    cin >> e;
    cout << "If u want find maximum enter 1 or enter any value for find minimum:";
    cin >> select;
    if(select == 1){
        cout << GoldenRatio::max(a, b, e);
    } else {
        cout << GoldenRatio::min(a, b, e);
    }
}