Seasons - Swich-case

using System;

    class Program
    {
        private static void Main()
        {
        int monthNumber = int.Parse(Console.ReadLine());
        string season;

        switch (monthNumber)
        {
            case 12:
            case 1:
            case 2:
                season= "Winter";
                break;

            case 3:
            case 4:
            case 5:
                season = "Spring";
                break;

            case 6:
            case 7:
            case 8:
                season = "Summer";
                break;

            case 9:
            case 10:
            case 11:
                season = "Autumn";
                break;

            default:
                season = "Error!";
                break;
        }

        Console.WriteLine(season);

        }
    }