PROGRAMMING:JMU piecewise function L

This topic requires the calculation of the value of the following piecewise function (x is an arbitrary real number entered from the keyboard)

If the input is not a number, "input error!" is output
###Input format:
Enter a real number x on one line.
###Output format:
Output in the format of "y = result" in one line, where result retains two decimal places.
###Input example:
```in
-2
```
###Output example:
The corresponding output is given here. For example:
```out
y=3.00
```







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