Problem Statement

You are given a string S of even length consisting of lowercase English letters. Let |S| be the length of S, and S_i be the i-th character of S.
Perform the following operation for each $i = 1, 2, \ldots, \frac{|S|}{2}$ in this order, and print the final S.

• Swap S_{2i-1} and S_{2i}.

Input

The input is given from Standard Input in the following format:
S

Output

Print the answer.

Constraints

• S is a string of even length consisting of lowercase English letters.
• The length of S is at most 100.

Sample Input 1

abcdef

Sample Output 1

badcfe

Initially, S = abcdef.
Performing the operation for i = 1 swaps S_1 and S_2, making S = bacdef.
Performing the operation for i = 2 swaps S_3 and S_4, making S = badcef.
Performing the operation for i = 3 swaps S_5 and S_6, making S = badcfe.
Thus, badcfe should be printed.

Sample Input 2

aaaa

Sample Output 2

aaaa

Sample Input 3

atcoderbeginnercontest

Sample Output 3

taocedbrgeniencrnoetts

见题面 Input 部分

见题面 Output 部分