Sorted Union array access

Tell us what’s happening:
I can not access to array element???
example: arr[0][1] does not return anything!

Your code so far

function uniteUnique(arr) {
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  return arr[0][1];
}

uniteUnique([1, 3, 2], [1, [5]], [2, [4]]);

Your browser information:

Your Browser User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36.

Link to the challenge:
https://www.freecodecamp.org/challenges/sorted-union

Thanks for reply, i figure out problem :smiley: