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# J, 5 char

```
2>#~.
```

**How it works:**

'~.' produces list of unique elements of list on its right

'#' counts how many elements in the list on its right

'2>' tests if number on its right only has one unique element


**Sample runs:**

   2>#~. 3 3 3 4

0

   2>#~. 3 3 3 3 

1