((long)Math.Round(d+45)/90)*90 % 360

    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine(Round(12));
            Console.WriteLine(Round(92));
            Console.WriteLine(Round(183));
            Console.WriteLine(Round(274));
            Console.WriteLine(Round(350));
        }

        static int Round(int value)
        {
            var edges = new[] { 0, 90, 180, 270, 360 };

            var q =
                from e in edges
                let d = Math.Abs(value - e)
                orderby d
                select e;

            return q.First();
        }
    }