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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class Main {
	//C問題

	public static void main(String[] args) throws IOException {

		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		Scanner scan = new Scanner(System.in);

		int n, k;

		n = scan.nextInt();
		k = scan.nextInt();

		List<Integer> amariList = new ArrayList<>();

		while (true) {
			int sho;
			int amari;

			sho = n / k;
			amari = n % k;

			amariList.add(amari);

			n = sho;

			if (sho == 0) {
				break;
			}
		}

		System.out.println(amariList.size());
	}

}