# 12. Up and Down

## I'm a slow walker, but I never walk backwards.

Write a program to read a positive integer $n$, then print a sequence of $2n-1$ integers from 1 to $n$, and then from $n-1$ to 1.

## Input Format

There are one line in the input. The first line has the integer $n$.

## Output Format

There are $2n-1$ lines in the output, according to the description.

## Sample Input

5


## Sample Output

123454321