B'You are given a tree with n vertices. You are allowed to modify the structure of the tree through the following multi-step operation: As an example, consider the following tree: The following diagram illustrates the sequence of steps that happen when we apply an operation to vertices 2 , 4 , and 5 : It can be proven that after each operation, the resulting graph is still a tree. Find the minimum number of operations that must be performed to transform the tree into a star. A star is a tree with one vertex of degree n - 1 , called its center, and n - 1 vertices of degree 1 . The first line contains an integer n ( 3 <= n <= 2 cdot 10^5 ) -- the number of vertices in the tree. The i -th of the following n - 1 lines contains two integers u_i and v_i ( 1 <= u_i, v_i <= n , u_i neq v_i ) denoting that there exists an edge connecting vertices u_i and v_i . It is guaranteed that the given edges form a tree. Print a single integer -- the minimum number of operations needed to transform the tree into a star. It can be proven that under the given constraints, it is always possible to transform the tree into a star using at most 10^{18} operations. The first test case corresponds to the tree shown in the statement. As we have seen before, we can transform the tree into a star with center at vertex 5 by applying a single operation to vertices 2 , 4 , and 5 . In the second test case, the given tree is already a star with the center at vertex 4 , so no operations have to be performed. '...