Salome is a lovely girl, and she is a extreme fan of milk tea. She is a super VIP of Coco, and now she wants to reach all the Coco shops in the world. All the Coco shops are connected as a tree, and the root is the head office. If there is a road between two Coco shops, Salome can go from one to another cost 1. Salome can also go back to head office immediately from any shop cost 0. Initially, Salome go from the head office(node 1), but Salome is short with algorithms. She wants to know the minimum cost if she want to reach all the shops, please tell her the minimum cost.