1004 Counting Leaves（DFS）：邻接表版：内容详尽

A family tree structure is commonly represented through a pedigree chart. Your task involves calculating the number of family members without any descendants.

Input Specification:

每个输入文件包含一个测试案例。
每个测试案例始于一行数据：其中包含树中的节点数量为介于
0 和 100 之间的整数 N，
以及非根节点的数量 M（且 M < N）。
随后会跟随 M 行数据，
每一行都按照以下格式排列：

Here's how it can be rewritten:
Each node is denoted by a two-digit number, where K represents the number of its child nodes. These child nodes are also represented by two-digit numbers following their parent's identifier. To simplify the notation, let us set the root's ID to 01.

The input