e-olymp
Problems

Command of the Mayor

Command of the Mayor

To ensure victory in the elections, the mayor decided to build a team of his friends, where everyone is a friend of each other. Knowing the relationship between an all N acquaintances mayor to build a team the greatest number of M. When the existence of multiple solutions is sufficient to derive only one of them.

Input

The first line is a single number N - the number of acquaintances Mayor (N < 50). In the second row - the number of K - the number of couples who have friendly relations. The following K lines through space-separated pair of numbers - numbers of friends.

Output

The first line of a single number - the largest squad of the mayor. The next line through the gap of the mayor's team in ascending numerical order.

Time limit 1 second
Memory limit 64 MiB
Input example #1
5
6
1 2
2 3
1 3
3 5
1 5
5 2
Output example #1
4
1 2 3 5