During a high-traffic sale day, one of your Amazon Kinesis Streams is experiencing increased traffic. To handle this, your Kinesis Administrator has split the shards, increasing the number from 6 to 10 shards in the Kinesis Stream. Your consumer application, which processes this data, is based on the Kinesis Client Library (KCL) and runs on EC2 instances.

Given this scenario, what is the maximum number of EC2 instances that can be deployed to process these 10 shards?