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;

namespace ConsoleApp1
{
    public class Person
    {
        public string firstName;
        public string lastName;
        public void Introduce()
        {
            Console.WriteLine("My name is " + firstName + " " + lastName);
        }
        public Person(string a = "HAHAa", string b =  "VCCAVA")
        {
            this.firstName = a;
            this.lastName = b;
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            int N, K;
            var a = Console.ReadLine().Split(' ');
            Int32.TryParse(a[0], out N);
            Int32.TryParse(a[1], out K);
            //Console.WriteLine("N : {0}, K: {1}", N, K);
            if (K == 10)
            {
                Console.WriteLine(a[0].Length);
            }
            else
            {
                int cnt = 0;
                while (N >= 1)
                {
                    N /= K;
                    cnt++;
                }
                Console.WriteLine(cnt);
            }
        }
    }
}