##Seriously, 7 bytes ' ;,@j+ [Try it online!](http://seriously.tryitonline.net/#code=JyA7LEBqKw&input=ImZvbyBiYXIi) Man, that required ending space added 3 additional bytes. Without it, `,' j` would work for 4. Explanation: ' ;,@j+ ' ; push two copies of a single space ,@ push input, swap j+ join on spaces, append a space