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)
    {
        var sol = new Solve();
        sol.Exec();
    }
}

class Solve
{
    public void Exec()
    {
        var l = Console.ReadLine().Split().Select(int.Parse).ToArray();
        int N = l[0], K = l[1];

        var ans = "";
        while (N > 0)
        {
            var rem = N % K;
            N /= K;
            ans += rem;
        }

        Console.WriteLine(ans.Length);
    }
}