Here's a short letter
I wish to invite you to join our school's project team to visit our sister school Bayswater College in London. We will be visiting famous tourist sites and staying with students from our sister school. The estimated cost will be 400litai. Our Deputy Principals Mrs Stumbriene and Mr Brangus will accompany our project team. Please let me know personally at Kedainiai High School or on my mobile number xxxxxxxxxxx by the end of the month if you can join us.