Task: Question Answering
Input (English): Context: Nearly a quarter century after a German boy threw a message in a bottle off a ship in the Baltic Sea, he's received an answer. A 13yearold Russian, Daniil Korotkikh, was walking with his parents on a beach when he saw something lying in the sand. "I saw that bottle and it looked interesting, " Korotkikh told The Associated Press on Tuesday."It looked like a German beer bottle and there was a message inside." It said, "My name is Frank, and I'm five years old.My dad and I are travelling on a ship to Denmark.If you find this letter, please write back to me, and I will write back to you." The letter, dated 1987, included an address in the town of Coesfeld. The boy in the letter, Frank Uesbeck, is now 29.His parents still live at the letter's address. The Russian boy and the German man met each other earlier this month through an Internet video link.The Russian boy said he did not believe that the bottle actually spent 24 years in the sea.He believed it had been hidden under the sand where he found it for a long time. Uesbeck was especially happy that he was able to have a positive effect on a life of a young person far away from Germany."It's really a wonderful story, " he said."And who knows? Perhaps one day we will actually be able to arrange a meeting in person." 
 Question: What is this passage mainly about?
Output (English): message in a bottle.