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: Accepted)

using System;
using System.Linq;
using System.Collections.Generic;

class Program
{
	static void Main(string[] args)
	{			
		//文字列を読み込む
		int[] input = Console.ReadLine().Split(' ').Select(i => int.Parse(i)).ToArray();
		int N = input[0];
		int K = input[1];
		
		int answer = Convert(N, K).Length;
		
		Console.WriteLine(answer);
      
	}

     public static string Convert(int x, int n)
	{
		string result = "";
		while(x > 0){
				result += (x%n).ToString();
				x /= n;
		}
		return result;
	}
}