P24318 [AtCoder] 1 2 1 3 1 2 1
入门
题目描述

Problem Statement

We define sequences S_n as follows.

  • S_1 is a sequence of length 1 containing a single 1.
  • S_n (n is an integer greater than or equal to 2) is a sequence obtained by concatenating S_{n-1}, n, S_{n-1} in this order.

For example, S_2 and S_3 is defined as follows.

  • S_2 is a concatenation of S_1, 2, and S_1, in this order, so it is 1,2,1.
  • S_3 is a concatenation of S_2, 3, and S_2, in this order, so it is 1,2,1,3,1,2,1.

Given N, print the entire sequence S_N.

Input

Input is given from Standard Input in the following format:
N

Output

Print S_N, with spaces in between.

Constraints

  • N is an integer.
  • $1 \leq N \leq 16$

Sample Input 1

2

Sample Output 1

1 2 1

As described in the Problem Statement, S_2 is 1,2,1.

Sample Input 2

1

Sample Output 2

1

Sample Input 3

4

Sample Output 3

1 2 1 3 1 2 1 4 1 2 1 3 1 2 1

  • S_4 is a concatenation of S_3, 4, and S_3, in this order.
输入格式

见题面 Input 部分

输出格式

见题面 Output 部分

样例输入
2
样例输出
1 2 1