PROGRAMMING:Case conversion

Enter a line of characters and end with carriage return '\ n'. Convert the upper case letters to the corresponding lower case letters and output them. Convert the lower case letters to the corresponding upper case letters and output them. Output other characters as they are.
###Input format:
Enter a line of characters ending with a carriage return '\ n'.
###Output format:
The upper case letters in the input string are converted to the corresponding lower case letters for output, the lower case letters are converted to the corresponding upper case letters for output, and other characters are output as is.
###Input example:
```in
Reold 123?
```
###Output example:
```out
rEOLD 123?
```







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