using System;

using Degrees = System.Double;

using System.Diagnostics;

​

public class Program

{

    public static void Main()

    {

        var pt = new GeoPoint(0, 0);

        for (var i = 0; i < 10; ++i)

        {

            pt.Move(5, 30);

            Console.WriteLine(pt);

        }

    }

​

    class GeoPoint

    {

        public GeoPoint(Degrees latitude, Degrees longitude)

        {

            _latitude = latitude;

            _longitude = longitude;

            Normalize();

        }

​

        private Degrees _latitude;

        private Degrees _longitude;

        private void Normalize()

        {

            _latitude = Math.Max(Math.Min(_latitude, 90), -90);

            while (_longitude <= -180)

                _longitude += 360; // inefficient, but clear

            while (_longitude > 180)

                _longitude -= 360; // inefficient, but clear

            Debug.Assert(_latitude >= -90 && _latitude <= 90);

            Debug.Assert(_longitude > -180 && _longitude <= 180);

        }

​

        public override string ToString() => string.Format($"{_latitude}, {_longitude}");

        public void Move(Degrees latitudeChange, Degrees longitudeChange)

        {

            _latitude += latitudeChange;

            _longitude += longitudeChange;

            Normalize();

        }

    }

}