IMAP: How to remove the recent flag?

Question

Email

Hello.

How to properly "read" emails with imap?
Select mailbox: EXAMINE INBOX
Search for new messages: SEARCH RECENT
Server response:

a5 SEARCH RECENT
* SEARCH 27
a5 OK Search completed (0.001 + 0.000 secs).

I read the message: FETCH 27 BODY[]

But after that it SEARCH RECENTcontinues to return letter No. 27. How to read a letter so that the RECENT flag is removed from it?

UPD: The task is as follows. It is necessary to write a program that once every N seconds checks the mailbox for new messages. If there is a new letter, then displays it. By condition, you must use the \Recent flag to determine new mail