Problem:
Score : 200 points

Problem Statement

Given is an integer N. Find the number of digits that N has in base K.

Notes

For information on base-K representation, see Positional notation - Wikipedia.

Constraints

All values in input are integers.

1 \leq N \leq 10^9

2 \leq K \leq 10

Input

Input is given from Standard Input in the following format:

N K

Output

Print the number of digits that N has in base K.

Sample Input 1

11 2

Sample Output 1

4

In binary, 11 is represented as 1011.

Sample Input 2

1010101 10

Sample Output 2

7

Sample Input 3

314159265 3

Sample Output 3

18

Solution in C# (Mono 4.6.2.0) (judge verdict: Runtime Error)

using System;
using System.Collections.Generic;
using System.Windows;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Atcoder
{
    public class Program
    {
        private static List<string> s = new List<string>();

        static void Main(string[] args)
        {
            var r = Console.ReadLine().Split(' ');
            var N = r[0].ToDecimal();
            var K = r[1].ToInt();
            Create(K, N);
            s.Reverse();
            Console.WriteLine(string.Join(string.Empty, s).ToDecimal());
            Console.ReadLine();
        }

        private static void Create(int K, decimal value)
        {
            s.Add((value % K).ToString());
            if (value > 0)
            {
                Create(K, Math.Floor(value / K));
            }
        }
    }
}

public static class Extentions
{
    public static int ToInt(this object obj)
    {
        return int.Parse(obj.ToString());
    }

    public static decimal ToDecimal(this object obj)
    {
        return decimal.Parse(obj.ToString());
    }

    public static double ToDouble(this object obj)
    {
        return double.Parse(obj.ToString());
    }
}