using System;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        double[] tests = new double[] {

            1.0,

            1123.1,

            1123.0,

            1122.9,

            1122.1,

            1122.0,

            1121.5,

        };

        foreach (var item in tests)

        {

            Console.WriteLine(item + " -> " + RoundToNearestEven(item));

        }

    }

    private static long RoundToNearestEven(double value)

    {

        return (long)value + (long)value % 2;

    }

}