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;

namespace ABC156B
{
    class MainClass
    {
        public static void Main(string[] args)
        {
            int[] nk = Console.ReadLine().Split().Select(int.Parse).ToArray();
            
            Console.WriteLine(IntToNString(nk[0],nk[1]).Length);
        }

        public static string IntToNString(int x, int n)
        {
            var nstring = "";
            var numbers = new string[] { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "e", "f" };
            int r = 1;  // 余り
            int q = x;  // 商

            // 商が0になるまでループ
            while (q > 0)
            {
                r = q % n;
                nstring += numbers[r];
                q = q / n;
            }
            return string.Join("", nstring.Reverse());
        }
    }
}