ENG  RUSTimus Online Judge
Online Judge
Problems
Authors
Online contests
About Online Judge
Frequently asked questions
Site news
Webboard
Links
Problem set
Submit solution
Judge status
Guide
Register
Update your info
Authors ranklist
Current contest
Scheduled contests
Past contests
Rules

1758. Bald Spot Revisited 2

Time limit: 1.0 second
Memory limit: 64 MB
Travis wanted to relax and took a walk round the town's pubs. Sitting at the first pubs, he realized that walking round the pubs one after another was not interesting at all, so he numbered all the pubs in the town from 1 to n starting from the pub he was sitting in and decided to move from one pub to another only if the number of one of them divided the number of the other. Naturally, Travis wanted to know how many pubs he could visit if he followed this rule and didn't visit any pub more than once.
Why would Travis be up to such a strange amusement? The point is that he is a louse living on the head of the eccentric mathematician Professor Pilgarlic. Help Professor and his little friend answer the intriguing question.

Input

The only input line contains the number n  of pubs in the town (2 ≤ n ≤ 50).

Output

In the first line output the maximal number of pubs Travis can visit. In the second line, output the numbers of these pubs separated with a space in the order of visiting. Remember that the route must start at the first pub. If there are several solutions, output any of them.

Sample

inputoutput
9
7
1 9 3 6 2 4 8
Problem Author: Ekaterina Vasilyeva
Problem Source: XI USU Open Personal Contest (March 13, 2010)