如何在Cloudformation模板中创建可变数量的EC2实例资源？

Parameters:
  InstanceCount:
    Type: Number
    Default: 1
    Description: The number of EC2 instances to create

Resources:
  MyEC2Instances:
    Type: AWS::CloudFormation::WaitConditionHandle
  MyEC2InstanceGroup:
    Type: AWS::CloudFormation::Init
    Properties:
      ConfigSets:
        default:
          - myConfig
      myConfig:
        commands:
          01_createInstances:
            command: !Sub |
              #!/bin/bash
              for i in $(seq 1 ${InstanceCount})
              do
                aws ec2 run-instances --image-id ami-12345678 --count 1 --instance-type t2.micro
              done
        services:
          sysvinit:
            cfn-hup:
              enabled: true
              ensureRunning: true
              files:
                - /etc/cfn/cfn-hup.conf
                - /etc/cfn/hooks.d/cfn-auto-reloader.conf
              commands:
                01_restart_cfn_hup:
                  command: service cfn-hup restart
  MyWaitCondition:
    Type: AWS::CloudFormation::WaitCondition
    DependsOn: MyEC2InstanceGroup
    Properties:
      Handle: !Ref MyEC2Instances
      Timeout: '300'

Outputs:
  MyEC2InstanceIds:
    Value: !Join [",", !GetAtt MyEC2InstanceGroup.InstanceIds]
    Description: The IDs of the created EC2 instances