Lost in Pajamas (1967)

Tanya, a 10-year-old Russian tourist traveling with her parents from Prague to Brno, is left behind in a foreign country. Tanya leaves her compartment when the train stops because of a cow. Disobeying her parent's instructions, she gets off the train to investigate, lingers too long, and is left behind. Cold, lonely, and clad only in her pajamas in the unfamiliar countryside, the girl is relieved to meet up with two rather nervous Czech boys camping out together for the first time. At first the would-be "cowboys" are frightened by her ghost-like appearance. After hearing her story, the boys find Tanya a dress to wear and accompany the girl on foot to her final destination, Brno.