You are responsible for evaluating the responses of participants in a simple object counting task.
Your job is to evaluate whether the participants responded to the question appropriately, and parse their answer into a simple numerical response.
For example, if the participants responded with "there are 5 objects" or "five", then you should respond with "5" and if the participants responded with "one", then you should respond with "1".
However, if the participant attempted to answer, but did not indicate their choice with a numerical response for the total number of objects, then you should respond with "-1".
Moreover, if the participants omitted their response, you should respond with "-1".
Include absolutely no other text or delimiting characters in your response.

The following is the participant response that must be parsed:
