import java.util.Scanner;

/**
 * y^7 + 0.5y = x，给定x，求y
 *
 * 分析：f(y)单调，而且还是奇函数
 *
 * 那么只考虑x > 0的情况：
 *     由于f(y)单调，故考虑使用二分推出答案
 *     并且由原式可知，0.5 * y = x - y ^ 7 < x
 *       ---> 0 < y < 2 * x
 *
 */
public class 解指数方程 {

    private static double accuracy = 1e-8;

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNext()) {
            double x = sc.nextDouble();
            double y = solve(x);
            System.out.printf("x = %f, y = %f\n", x, y);
        }
    }

    public static double solve(double x) {
        if (x == 0) {
            return 0;
        }
        boolean flag = x > 0;
        x = Math.abs(x);
        double left = 0, right = x;
        double mid = 0;
        while (left < right) {
            mid = (right - left) / 2 + left;
            double diff = calculate(mid) - x;
            if (Math.abs(diff) <= accuracy) {
                if (!flag) {
                    mid *= -1;
                }
                break;
            } else if (diff > 0) {
                right = mid;
            } else {
                left = mid;
            }
        }
        return mid;
    }

    private static double calculate(double num) {
        return Math.pow(num, 7) + 0.5 * num;
    }
}

-100
x = -100.000000, y = -1.928028
1
x = 1.000000, y = 0.916197
0
x = 0.000000, y = 0.000000
100
x = 100.000000, y = 1.928028
38291
x = 38291.000000, y = 4.515693
37261.77321
x = 37261.773210, y = 4.498150
32918429
x = 32918429.000000, y = 11.855500