Extra E aside does anyone know why the expected result is different?

Input WEAREDISCOVEREDFLEEATONCE rails = 2.

Expected was WADCEFACTLROIREESVEEOENED but my result was WAEICRLTEEOSDREEICVDEOAFE

Manually working this out also gave me

W A E I C V R D L E T N E
 E R D S O E E F E A O C

Hi, there is a small error in the rail that you wrote above. If you look closely, there is an extra "E" in your "DISCOVEREED". I hope this helps and happy coding (sorry, I see that this question is from a month ago, but I just completed the exercise).

Can someone explain how this output is the correct answer:

Input: WEAREDISCOVEREDFLEEATONCE

with n=2

the expected output is WADCEFACTLROIREESVEEOENED

but even working it out manually I find the answer to be WAEICVRDLETNEERDSOEEFEAOC (as take every other letter and put on one other rail)?
eg

W A E I C V R E F E A O C
 E R D S O E E D L E T N E