Multiple account with contacts in rest resource

@RestResource(urlMapping='/BulkInsertaccountcontact/*')
global class Bulkinsert_accountcontact
{
   global class RequestBody 
   {
       List<Account> adList; 
       List<Contact> cList;
   }
   global class myWrapper
   {
      List<Account> aList;
      List<Contact> cList;
      public string status;
      public string message;
   }
   @HttpPost
   global static myWrapper doPost(RequestBody rb)
   {
      RestRequest req=RestContext.request;
      RestResponse res=RestContext.response;
      myWrapper response=new myWrapper(); //this is object of wrapper class
      List<Account> myAList=new List<Account>();
      try
      {
        for(Account acn:rb.adList)
        {
          myAList.add(acn);
        }
        Insert myAList;
        response.aList=myAList;
        for(Contact con:rb.cList)
        {
          //
        }
        //we need to insert contact List also
        Insert rb.cList;
        response.cList=rb.cList;
        response.status='Success';
        response.message='Created Successfully';
      }
      catch(exception ex)
      {
         response.aList=null;
         response.cList=null;
         response.status='ERROR';
         response.Message='could not create record'+ ex.getMessage();
      }
      return response;
   }
}
In workbench I will enter the following Json format for inserting Multiple accounts and each account will have 2 contact records or more..
{
    "rb": {
        "a": {
            "Name": "LG1",
            "SLAExpirationDate__c": "2016-4-21",
            "Active__c": "Yes",
            "SLA__c": "Platinum",
            "SLASerialNumber__c": "200"
        },
        "cList": [{
            "FirstName": "K1",
            "LastName": "K2"
        }, {
            "FirstName": "K3",
            "LastName": "K4"
        }]
    },
    "b": {
        "Name": "LG2",
        "SLAExpirationDate__c": "2016-4-21",
        "Active__c": "Yes",
        "SLA__c": "Platinum",
        "SLASerialNumber__c": "200"
    },
    "cList": [{
        "FirstName": "K5",
        "LastName": "K6"
    }, {
        "FirstName": "K7",
        "LastName": "K8"
    }]
}