I'm a novice and had this thought. I understand that data in an existing block can't be altered, as it changes the hash. But what if, before creating the block, I take transactions from the pool, alter one transaction, and then proceed to create the block? Let's say I have the most powerful hardware and finish it before other miners. Will other nodes be able to verify the transaction data inside the block? (example: say A sends 10 tokens to B, and I change that to 100. A has 200 tokens in his wallet)