Bl lu ur rr ry yv vi is si io on - Blur the text Task

Given a string as input, generate a "blurred" version of that string.

Input

Your input will be a single-line string of ASCII characters, containing a minimum of 2 alphanumeric characters

Output

A string that is the "blurred" version of the input string.

A blurred string is one where every alphanumeric character from the original string has been paired with the ones adjacent to it, and each pair is separated by a space.

Any non-alphanumeric characters (whitespace, puncuation) in the input string must be ignored when determining adjacency of alphanumeric characters, and they must not included in the blurred string.

There must be no leading or trailing whitespace in the output string.

Examples

Ab -> Ab
Abc -> Ab bc
Abcd -> Ab bc cd
E?h? -> Eh
Blurry vision -> Bl lu ur rr ry yv vi is si io on
We're #1! -> We er re e1
I'm an example! -> Im ma an ne ex xa am mp pl le
This is _not_ legible -> Th hi is si is sn no ot tl le eg gi ib bl le
(a*b*c)+5^-x -> ab bc c5 5x
??a_%,1!=z#@ -> a1 1z 



This is code-golf, so fewest bytes wins!
Python 3, 57 55 bytes



lambda s:"".join((c+" "+c)*c.isalnum()for c in s)[2:-2]


Try it online!

How:


For each alpha-numeric character c in the string, replace it with c+" "+c.
E.g: "abcd" -&gt; "a ab bc cd d"
Remove the redundant first and last 2 characters:
E.g: "a ab bc cd d" -&gt; "ab bc cd"