1. I will visit newest submissions on reddit

2. I will pick the titles of the first 3 newest submissions and concatenate them in newest-to-oldest order in a string like this --> "this was posted right nowthis is the second titlethis is the title of the last one"

3. I will find the MD5 hash (in hex) of the string in step 2

4. I will generate a random sequence from 0 - 1023 using the hash found on step 3 as a persistent identifier on random.org/sequences (you can see a sample configuration here: random.org configuration)

5. I will then go through each line of the random sequence until there is a collision with a number posted here in the comments

This is how I'll check for number collisions in the random sequence and also check if they are valid:

1.  Read the first number
2.  If the number appeared in the comments, go to #5
3.  Read the next number
4.  Go to #2
5.  Add comments in the candidate pool
6.  Take out candidate users that posted a number twice
7.  Take out candidate users that are <30 days old
8.  Take out candidate users that have <150 comment karma
9.  If there are no candidate users left go to #3
10.  If only 1 candidate user left go to #15
11.  If the oldest post from the candidate pool has a matching timestamp with another one from the candidate pool, go to #13
12. Go to #9
13. Take out all candidates from the pool that have the same timestamp as the oldest
14. Go to #9
15. DING DING DING! We have a winner

edit 2: Giveaway is closed I'll find the winner a bit later

here are the data:
string: Las campanadas YA HAN SONADO.Soupy 2020Staying the Course on Nuclear Modernization
md5 sum: 8172348E4C93CA31D991422B1408C5F4
random sequence: random.org

edit 3: winner is /u/MateiSalgau with 137! (number place 106 in the random sequence)
the winning comment

I PM'd the winner