using System.Collections.Generic;
using System.Threading.Tasks;
public static void Main()
Console.WriteLine("Hello, World!");
Console.WriteLine("Two await false");
await A().ConfigureAwait(false);
await B().ConfigureAwait(false);
Console.WriteLine("Two await true");
await A().ConfigureAwait(true);
await B().ConfigureAwait(true);
Console.WriteLine("No await");
await Task.WhenAll(a, b).ConfigureAwait(false);
Console.WriteLine("Bye, World!");
for (int i = 0; i < 10; i++)
Console.WriteLine($"A: {i}");
for (int i = 0; i < 15; i++)
Console.WriteLine($"B: {i}");