Randomness generation mechanism is wrong
never use block.number , block.timestamp for generating the random number becuase it can be easily exploited by attacker
any user can generate random number on its own and can get type of coin what user wants
Manual
not use block.timestamp , block,number for random value generation
The contest is live. Earn rewards by submitting a finding.
This is your time to appeal against judgements on your submissions.
Appeals are being carefully reviewed by our judges.