Write returning(jan, feb) returning the customers who bought in both months, sorted A–Z.
returning(['Asha', 'Ravi', 'Om'], ['Om', 'Kiran', 'Asha']) → ['Asha', 'Om']
returning([], ['A']) → []
Submit runs 3 tests, including hidden edge cases.
Each hint gives a little more help. Try on your own first.
Run your code to see the output here.