Summarize the letter.

The letter is from Olga to Anna, describing her exciting summer holidays spent with her grandparents in the countryside. She mentions helping her grandma in the garden, picking strawberries, going for walks in the forest, listening to birds, and fishing with her grandad. Olga also mentions returning home and preparing for the new school year, looking forward to seeing friends and teachers. She asks Anna to write back and share about her summer.