Đổi chỗ từng cặp kề nhau (Swap Adjacent Pairs)

Source: Phước Hưng OJ

Version: Phuoc Hung OJ Extended

Problem

Given an integer array $a_1,a_2,\ldots,a_n$.

Swap consecutive elements pair by pair from left to right:

If $n$ is odd, the final element $a_n$ has no partner and remains unchanged.

Let the resulting array be $b$. For every $k$ such that $2k\le n$,

If $n$ is odd, additionally $b_n=a_n$.

Print $b$.

Input

The first line contains integer $n$. The second line contains $n$ space-separated integers $a_1,a_2,\ldots,a_n$.

Output

Print the $n$ elements after swapping adjacent pairs on one line.

Subtasks

Subtask 1 (100 points): $1\le n\le 2\cdot 10^5$; $|a_i|\le 10^9$.

Example

Input

7
1 2 3 4 5 6 7

Output

2 1 4 3 6 5 7

Explanation

The pairs $(1,2)$, $(3,4)$, and $(5,6)$ are swapped; the final value $7$ remains unchanged.