Third Root

The solution of $x ^ 3 = q$ is to calculate the recurrence formula $ x_ {n + 1} = x_n-\ frac {x_ {n} ^ 3 --q} {3x_ {n} ^ 2} $ It can be calculated approximately with.

Put a positive number $\ frac {q} {2}$ in $x_1$

$x_2 = x_1-\ frac {x_ {1} ^ 3 --q} {3x_ {1} ^ 2}$, $ x_3 = x_2-\ frac {x_ {2} ^ 3 --q} {3x_ {2} ^ Calculate as 2} $,….

While doing this calculation

When the value of $| x ^ 3 --q |$ becomes small enough, stop the calculation and use the last calculated $x_n$ as an approximate solution of $x ^ 3 = q$.

Follow this method to create a program that outputs an approximation of the cube root of $q$ for the input positive integer $q$. However, use $| x ^ 3-q | <0.00001 q$ to determine that it is "small enough".

input

Multiple datasets are given. For each dataset, $q$ ($1 \ leq q <2 ^ {31}$) (integer) is given on one line. The end of the input is -1.

The number of datasets does not exceed 50.

output

Print $x$ (real number) on one line for each dataset. The output result may contain an error of 0.00001 or less.

Example

Input

15 15 -1

Output

2.466212 2.466212

inputFormat

outputFormat

outputs an approximation of the cube root of $q$ for the input positive integer $q$. However, use $| x ^ 3-q | <0.00001 q$ to determine that it is "small enough".

input

Multiple datasets are given. For each dataset, $q$ ($1 \ leq q <2 ^ {31}$) (integer) is given on one line. The end of the input is -1.

The number of datasets does not exceed 50.

output

Print $x$ (real number) on one line for each dataset. The output result may contain an error of 0.00001 or less.

Example

Input

15 15 -1

Output

2.466212 2.466212

样例

15
15
-1

2.466212
2.466212

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