JSON в C#

using System;
using System.Text.Json;

public record Root(
	[property: JsonPropertyName("a")]
	string A,
	[property: JsonPropertyName("arr")]
	int[] Arr,
	[property: JsonPropertyName("nested")]
	Nested Nested
);

public record Nested(
	[property: JsonPropertyName("a")]
	int A,
	[property: JsonPropertyName("b")]
	string B
);