Please identify all the named entities mentioned in the input sentence provided below. Use only the categories: PER - person, ORG - organization, and LOC - location.
Remember, nationalities are neither locations nor organizations, and organizations can represent other groups of people.
Pay attention to the provided example. You should only output the results in JSON format, following a similar structure to the example result provided.

Example sentence and results:

Where in the world is Iguazu?

"Results": [
    {
        "TypeName": "LOC",
        "Text": "Iguazu",
        "Start": 22,
        "End": 28
    }
]

Considering the input sentence below, what is the output result?

In the Oct. 31 letters, electricity producers told federal officials that if price caps were n't removed it would lead to a collapse of the energy market.


"Results": []