using System;

using System.Threading;

using System.Threading.Tasks;

public class Program

{

    public async static Task Main()

    {

        using var cts = new CancellationTokenSource(1000);

        await Parallel.ForEachAsync(new[]{1, 2}, cts.Token, async (value, ct) => {

            if(value == 1)

                throw new Exception("1");

            try

            {

                await Task.Delay(3000, ct);

            }

            catch (OperationCanceledException)

            {

                Console.WriteLine("canceled: " + value);

                throw;

            }

            Console.WriteLine(value);

        });

        Console.WriteLine("Hello World");

    }

}