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 atcoder
{
    class Program
    {
        static void Main(string[] args)
        {
            var line_input = System.Console.ReadLine();
            var split = line_input.Split(' ');
            int N = int.Parse(split[0]);
            int K = int.Parse(split[1]);

            int count = 1;
            while((Math.Pow(K,count)) <= N)
            {
                count++;
            }
            System.Console.WriteLine(count);
        }
    }
}