Thais, ground floor. The white circle is where he stands.

Start with hi. Then:

To buy

For several at once, say the number first: 10 letters.

Buy a letter or a parcel, write on it and drop it in a mailbox. Write the name of the receiver on the first line and the city on the second; a parcel carries the label inside.

It lands in that city's depot. Depots are free and what you leave in one is only yours.