Minimum number of boxes to be opened to find the treasure?

One thousand boxes are in a single row, and a precious pearl is hidden inside one of them.


You don't know which box has the pearl.


All the boxes have the same message written on them


Message: “The pearl is either inside the left box or inside the right box”.


Fortunately, we are given a hint that “only one of these boxes is telling the truth”.


Then, what is the minimum number of boxes you need to open to be sure about which box contains the pearl?

Pls help.