PROGRAMMING:Calculating piecewise function

This topic requires the calculation of the following piecewise function $$f (x) $:
![ Formula] (~ / 1)
###Input format:
The input gives the real number x on one line.
###Output format:
Output in the format of "f (x) = result" in one line, where both X and result retain one decimal place.
###Input sample 1:
```in
ten
```
###Output sample 1:
```out
f(10.0) = 0.1
```
###Input sample 2:
```
0
```
###Output sample 2:
```
f(0.0) = 0.0
```






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