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: Wrong Answer)

using System;
public class Program
{
    public static void Main(string[] args)
    {
        // 整数の入力
        string[] input = Console.ReadLine().Split(' ');
        int b = int.Parse(input[0]);
        int c = int.Parse(input[1]);
        int ans = 1;
        while (b > c)
        {
            b = b / c;
            ans++;
        }
        //出力
        Console.WriteLine(ans);
    }
}