Where is the final answer?

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Across
  1. 2. To or not?
  2. 4. Lost and...
  3. 6. To investigate
  4. 9. Needed for a problem
Down
  1. 1. Of the Head of Apartment Owners' Association
  2. 3. Don't put your phone in your back...
  3. 5. Soda in a bottle or a...
  4. 7. ___ or against?
  5. 8. Privacy for letters
  6. 10. __ or out?