Description

Martin has something wrong with his eyes.

For a word, each time he blinks, the letters of the word change in his eyes as follows (the phrases “the $k$-th from the end”, “the $k$-th”, etc. all refer to the word before the change):

• The last letter is moved to between the $1$-st and $2$-nd letters.
• The second-to-last letter is moved to between the $2$-nd and $3$-rd letters.
• $\ldots\ \ldots$
• The $k$-th letter from the end is moved to between the $k$-th and $(k+1)$-th letters.

For example, the word $\tt abcdef$ will become $\tt afbecd$ after he blinks.

If Martin blinks again, the same thing will happen again.

Given the number of times Martin blinks $X$ and the word $s$ that he sees, find the original word.

Input Format

The first line contains an integer $X$, representing the number of times Martin blinks.

The second line contains a string $s$, representing the word Martin sees.

Output Format

Output one line with one string: the original word.

4 
acefdb

abcdef

1000 
aaaaaa

aaaaaa

11 
srama

sarma

Hint

Explanation for Sample 1

The transformation process is: $\tt abcdef\to afbecd\to adfcbe\to aedbfc\to acefdb$.

Constraints

• For $50\%$ of the testdata, $1\le X\le 100$.
• For $100\%$ of the testdata, $1\le X\le 10^9$, $3\le |s|\le 10^3$.

Source

This problem is translated from COCI2013-2014 CONTEST 2 T3 SLOM.

According to the original testdata settings, the full score for this problem is $100$ points.

Translated by ChatGPT 5