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?

The ARVN was not having a big problem with the Local VC (the guerilla movement), they were being challenged by the Main Force VC (which was light infantry) and the North Vietnamese Army (NVA).


"Results": [
    {
        "TypeName": "ORG",
        "Text": "ARVN",
        "Start": 4,
        "End": 8
    },
    {
        "TypeName": "ORG",
        "Text": "Local VC",
        "Start": 47,
        "End": 55
    },
    {
        "TypeName": "ORG",
        "Text": "Main Force VC",
        "Start": 115,
        "End": 128
    },
    {
        "TypeName": "ORG",
        "Text": "North Vietnamese Army",
        "Start": 164,
        "End": 185
    },
    {
        "TypeName": "ORG",
        "Text": "NVA",
        "Start": 187,
        "End": 190
    }
]