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: Wrong Answer)

import java.util.Scanner;
import java.util.List;
import java.util.ArrayList;

public class Main {
  public static void main(String[] args){
    Scanner scanner = new Scanner(System.in);
    int N = scanner.nextInt();
    int K = scanner.nextInt();
    List<Integer>list = new  ArrayList<>();
    int amari = 0;
    for(;N > K;){
      amari = N % K;
      list.add(amari);
      N = N / K;
    }
    list.add(amari);
    if(N != 0)list.add(N);
    System.out.println(list.size());
  }
}