PROGRAMMING:Travel together in autumn
You can go for an autumn outing! Students, don't mention how happy! The teacher said, it's a little dangerous to act alone, so let's go together. The rules of company are as follows: the person at the top and the person at the bottom form a company, the person at the second and the person at the bottom form a company, and so on. OK, please line it up right away! As soon as the teacher's voice fell, the students "Shua Shua" soon got together, ready to start!
###Input format:
The first line is an integer n, indicating n students（ 2 < = n < = 50, n is even).
In the second line, n integers indicate the student numbers of n students, and there is a space between the student numbers.
###Output format:
A total of N / 2 lines, two integers in each line, indicating the student number of the companion students, and there is a space between the two student numbers.
###Input example:
```in
six
5 6 4 12 3 2
```
###Output example:
```out
5 2
6 3
4 12
```
answer：If there is no answer, please comment
###Input format:
The first line is an integer n, indicating n students（ 2 < = n < = 50, n is even).
In the second line, n integers indicate the student numbers of n students, and there is a space between the student numbers.
###Output format:
A total of N / 2 lines, two integers in each line, indicating the student number of the companion students, and there is a space between the two student numbers.
###Input example:
```in
six
5 6 4 12 3 2
```
###Output example:
```out
5 2
6 3
4 12
```
answer：If there is no answer, please comment