<center>https://cdn.discordapp.com/attachments/404587860872921088/405329216280723458/challenge.png</center>

For each tutorial we release there will be a relevant challenge where the winner receives 1 STEEM! 

### Challenge

Take the code from the tutorial from [here](https://github.com/amosbastian/steempy-tutorials/tree/master/part_17) and change it to be able to do the following

1. Instead of filtering for posts not older than 30 min, store the post and upvote after 30 min. Also only upvote if accounts in a separate list have already voted on the post.

That's it! Good luck to everyone participating!

### Deadline
The prize money will be rewarded to the person that solves the problem first. If there is no solution within 7 days after this post has been submitted the prize pool expires.

### Relevant Tutorial

[Part 17: 3 Methods To Prevent Double Voting On Posts](https://steemit.com/utopian-io/@steempytutorials/part-17-3-methods-to-prevent-double-voting-on-posts)

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If you have questions about the tutorial or the challenge then don't hesitate to comment below or contact us on [Discord](https://discord.gg/rYTV87W)!