﻿using System;
﻿using System.Globalization;
﻿using System.IO;
﻿using System.Linq;

namespace CF317
{
    internal class Program
    {
        private static void Main(string[] args)
        {
            var sr = new InputReader(Console.In);
            //var sr = new InputReader(new StreamReader("input.txt"));
            var task = new Task();
            using (var sw = Console.Out)
            //using (var sw = new StreamWriter("output.txt"))
            {
                task.Solve(sr, sw);
                //Console.ReadKey();
            }
        }
    }

    internal class Task
    {
        public void Solve(InputReader sr, TextWriter sw)
        {
            var input = sr.ReadArray(Int64.Parse);
            var n = input[0];
            var x = input[1];
                var result = x;
                var len = n - (n - x);
                if (len % (n - x) == 0) {
                    result += 2*len / (n - x);
                }
                else {
                    var r = (len / (n - x));
                    result += (2 * r + 1L) * (n - x);
                    var next = x - (r * (n - x));
                    if (next < 0) {
                        next = x;
                    }
                    if ((n - x) % next == 0) {
                        result += next * (2*((n - x) / next) - 1);
                    }
                    else {
                        result += next * 2;
                        result += x + 1;
                    }
                }
            sw.WriteLine(result);
        }
    }
}

internal class InputReader : IDisposable
{
    private bool isDispose;
    private readonly TextReader sr;

    public InputReader(TextReader stream)
    {
        sr = stream;
    }

    public void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    public string NextString()
    {
        var result = sr.ReadLine();
        return result;
    }

    public int NextInt32()
    {
        return Int32.Parse(NextString());
    }

    public long NextInt64()
    {
        return Int64.Parse(NextString());
    }

    public string[] NextSplitStrings()
    {
        return NextString()
            .Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
    }

    public T[] ReadArray<T>(Func<string, CultureInfo, T> func)
    {
        return NextSplitStrings()
            .Select(s => func(s, CultureInfo.InvariantCulture))
            .ToArray();
    }

    public T[] ReadArrayFromString<T>(Func<string, CultureInfo, T> func, string str)
    {
        return
            str.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries)
                .Select(s => func(s, CultureInfo.InvariantCulture))
                .ToArray();
    }

    protected void Dispose(bool dispose)
    {
        if (!isDispose)
        {
            if (dispose)
                sr.Close();
            isDispose = true;
        }
    }

    ~InputReader()
    {
        Dispose(false);
    }
}