This is the second solution, to see the first solution, check out the first-solution tag

cargo install styleth
styleth --regex "ffff$"

Put the generated addresses in addresses.json and run:

node look_for_zero.js

If no suitable address was found, go back to Step #1.

Once you've found a suitable address:

1. Enter its private key in hardhat.config.ts
2. Enter its block number in scripts/deploy.ts and test/Test.ts
3. Enter its public key in generate.js
4. Enter its odd numbers' sum in scripts/deploy.ts

npx hardhat run scripts/deploy.ts --network optimism

Enter the deployed contract's address in test/Test.ts

node generate.js

Once you have it, enter the puzzle solution in test/Test.ts

# for testing on a local hardhat forked node, uncomment the relevant code block in test/Test.ts and run
npx hardhat test

# for waiting for the target block number and the transmitting the TXs:
npx hardhat test --network optimism