PROGRAMMING:Word inversion
Write a program, read in a line of English (only contains letters and spaces, separated by a single space between words), invert the order of all words and output, still separated by a single space.
###Input format:
The input is a single line string.
###Output format:
The output is a string in reverse order as required.
###Input example:
```in
I am a student
```
###Output example:
```out
student a am I
```
answer：If there is no answer, please comment
###Input format:
The input is a single line string.
###Output format:
The output is a string in reverse order as required.
###Input example:
```in
I am a student
```
###Output example:
```out
student a am I
```
answer：If there is no answer, please comment