Hi, I am going to Thailand on the 24th of November and leaving the country on the 23rd of December. In that period of time I am also planning to fly to Vietnam and then comeback to Thailand. Do I need a special multiple entry visa? If yes, do I apply for that Visa on my first arrival in Thailand? Could someone explain to me how it works and whats the process?

Or can I take the single entry visa two times?

P.S.

Im a Lithuanian