代码如下

using System;
namespace ConsoleApp
{
    public class Program
    {
        public static void Main(string[] args)
        {
            string[] input = Console.ReadLine().Split(' ');
            int limit = int.Parse(input[1]);
            int GetSum(int smoke){
                if(smoke / limit < 1){
                    return smoke % limit;
                }else{
                    return smoke - smoke % limit + GetSum(smoke % limit + smoke / limit);
                }
            }
            Console.WriteLine(GetSum(int.Parse(input[0])));
        }
    }
}