Here is what i exactly did:
1. Generate the entire 64 range divided as 17,666,000 sub-ranges sorted sequentially at first.
2. Randomize the sub-ranges completely
3. Search each sub-range line by line, so that each sub-range completed gets me 1 in 17.6 million chance of winning.
After someone solved 64 and the pvt key was revealed, i found out that right sub-range after randomization was in line 1 million.
i.e: i was never meant to solve it if i kept going forward with this plan.
Ahhhh, gotcha...well it's not that you wouldn't have solved it with more resources.

At least you randomized the list somewhat. Sequential is brutal and defeating lol.