Problem Description

Consider the equation $a\ x^5\ +\ bx\ +\ c=0$ which satisfies the following condition:

• It has exactly one solution in the range $1\lt\ x\ \lt\ 2$

Calculate the solution of the equation that satisfies $1\lt\ x\ \lt\ 2$.

Input Format

The input is given from the standard input in the following format:

$ a $ $ b $ $ c $

Output Format

Output the answer.
The answer will be considered correct if the absolute or relative error from the expected answer is within $ 10^{-9} $.

Sample Input and Output

Sample Input #1

32 2 -246

Sample Output #1

1.500000000000000000

Sample Input #2

12 3 -45

Sample Output #2

1.279562760087743278

Notes/Hints

Constraints

• $1\ \leq\ a\ \leq\ 10^9$
• $1\ \leq\ b\ \leq\ 10^9$
• $-10^9\ \leq\ c\ \leq\ 10^9$
• All inputs are integers
• The given equation has exactly one solution in the range $1\lt\ x\ \lt\ 2$

Sample Explanation 1

When $x\ =\ 1.5$, it satisfies $ax^5+bx+c=32\times(1.5)^5\ +\ 2\times1.5\ -\ 246\ =\ 0$.

见题面 Input 部分

见题面 Output 部分