This means 'Hello' in Korean.
Lucas was paired up with one of his classmates to do a special assignment in school this past week - about Korea! Something that was quite a coincidence, since Granddad works there! (Kind of, he flies for Korean Airlines)
Lucas really enjoyed doing this homework, he did all his research on the internet, printed out the photos they needed and was really happy when he found the information he was looking for. He did a really good job!
Here's their finished result: