Workflow 2013 - passing array argument

Hi,

I got this simple workflow with composite task that looks like this:

As you can seen nothing fancy. For this workflow I also got a custom initiation form with a simple text box for entering account names. But apparently this is not how you should pass that argument:

wfParams['assignedTo'] = strInputValue.split(";");

I keep getting error when trying to start workflow:

An error occured when starting workflow. Type 'System.Object[]' with data contract name 'ArrayOfanyType:http://schemas.microsoft.com/2003/10/Serialization/Arrays' is not expected.

Is there any other way to pass arrays to workflow?