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 ConsoleApp1
{
    static class BDigits
    {
        static void Main(string[] args)
        {
            var s = Console.ReadLine().Split(' ');
            var n = int.Parse(s[0]);
            var k = int.Parse(s[1]);

            string conv = "";
            while (n > 0)
            {
                conv += (n % k).ToString();
                n /= k;
            }

            Console.WriteLine(string.Join("", conv.Reverse()).Length);
            Console.ReadLine();
        }
    }
}