题目

There was once a captain who loved money so much that he cheated his sailors at the end of every voyage and took their wages.On the last day of one voyage, the ship was in a small port. It was winter time, and the sea was very cold, so the captain said to his sailors, If one of you stays in the water during the whole night, I will give him my ship. But if he comes out before the sun appears, I shall get his wages.The sailors had heard about the captain's cheating, so they didn't trust him. But then one of them, who thought that he was cleverer than the captain, said that he would do it已知|OA|=4，|OB|=2，∠AOB=2π3，OC=xOA+yOB，且x+2y=1，则|OC|的最小值是277．