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

namespace ABC_156b
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] number = Array.ConvertAll(Console.ReadLine().Split(' '), int.Parse);
            List<int> S = new List<int>();
            while(number[0] > number[1] || number[0] == number[1])
            {
                S.Add(number[0] % number[1]);

                number[0] = number[0] / number[1];
            }
            
            Console.WriteLine(S.Count + 1);
            Console.Read();
        }
    }
}