When register on a social network, you are always asked to specify your hobbies in order to find some potential friends with the same hobbies. A “social cluster” is a set of people who have some of their hobbies in common. You are supposed to find all the clusters.

**Input Specification:**

Each input file contains one test case. For each test case, the first line contains a positive integer N (<=1000), the total number of people in a social network. Hence the people are numbered from 1 to N. Then N lines follow, each gives the hobby list of a person in the format:

K_{i}: h_{i}[1] h_{i}[2] … h_{i}[K_{i}]

where K_{i} (>0) is the number of hobbies, and h_{i}[j] is the index of the j-th hobby, which is an integer in [1, 1000].

**Output Specification:**

For each case, print in one line the total number of clusters in the network. Then in the second line, print the numbers of people in the clusters in non-increasing order. The numbers must be separated by exactly one space, and there must be no extra space at the end of the line.

**Sample Input:**

1 2 3 4 5 6 7 8 9 |
8 3: 2 7 10 1: 4 2: 5 3 1: 4 1: 3 1: 4 4: 6 8 1 5 1: 4 |

**Sample Output:**

1 2 |
3 4 3 1 |

用 Disjoint Sets 解决……

代码如下：