{ "VPC" : {
    "Type" : "AWS::EC2::VPC",
    "Properties" : {
      "CidrBlock" : {"Fn::Join" : [ ".", [{"Ref" : "VPCPrefix"}, "0.0/16"] ]},
      "Tags" : [
        {"Key" : "Application", "Value" : { "Ref" : "AWS::StackName"} },
        {"Key" : "Network", "Value" : "Public" }
      ]
    }
  }
}