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# (.NET Core 3.1.201) (judge verdict: Accepted)

using System;
using System.Linq;

namespace AtCoderPractice0704
{
    class MainClass
    {
        public static void Main(string[] args)
        {
            long[] NR = Console.ReadLine().Split(' ').Select(a => long.Parse(a)).ToArray();

            long  N = NR[0];
            long  K = NR[1];
            long ans=0;

            while (N /K >=1)
            {
                ans++;
                N /= K;
            }

            Console.WriteLine(ans+1);
        }
    }
}