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;
class Program {
    static void Main(string[] args) {
        string s = Console.ReadLine();
            long se = long.Parse(s.Split(' ')[0]);
            int sinnsuu = int.Parse(s.Split(' ')[1]);

            int i = 1;
            long l = 0;
            while (true)
            {
                l = 0;
                for(int a = 1;a != i; a++)
                {
                    if (a == 1)
                    {
                        l = sinnsuu;
                    }
                    else
                    {
                        l *= sinnsuu;
                    }
                }
                if(l < se){
                    i++;
                }
                else
                {
                    break;
                }
            }
            Console.WriteLine(l);
    }
}