Railfence Cipher

The railfence cipher scrambles the letters of a message. Below is an example of how to cipher a message using railfence

r		i		f		n		e
	a		l		e		c		a

This is how one would encode the word "railfence":

1. Draw up a grid as shown above
2. Write your message in as a zig-zag like above. Ignore spaces
3. If there is an odd number of characters, add a place filler letter in the last cell (shown in red)
4. Copy down all the letters from the first row, then the second row

and now "railfence" becomes "rifnealeca".