# [Nibbles], 7 bytes (14 nibbles)

    /|``p$/!>>$@!*
    
[Nibbles]: http://golfscript.com/nibbles/index.html

```
/|``p$/!>>$@!*
 |				 # filter
  ``p			 # all permutations of 
     $			 # the input list
     			 # by 
      /      *	 # fold-by-multiplication
       !		 #   zip together
        >>$		 #     list without first element
           @	 # 	   the same list
            !	 #     are elements equal?
/ 				 # finally get first element
```


[![enter image description here][1]][1]


  [1]: https://i.sstatic.net/vHUOH.png