PROGRAMMING:String positive and negative sequence connection

Enter a string, and the string is concatenated in reverse order at the end of the string.
###Input format:
Enter a string no longer than 10.
###Output format:
Output a new string formed by concatenating strings in reverse order after the current string.
###Input example:
```in
Here is a set of inputs. For example:
ABCD
```
###Output example:
```out
The corresponding output is given here. For example:
ABCDDCBA
```






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