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.util.Scanner;

/**
 * B - Digits
 * 整数 N を K 進数で表したとき、何桁になるかを求めてください。
 */
public class Main {

    public static void main(String[] args) {

        Scanner sc = new Scanner( System.in );
        // 整数N
        int n = sc.nextInt();
        // 何進法か
        int k = sc.nextInt();

        if( k == 10 ) {
            System.out.println( String.valueOf( n ).length() );
        }
        else {
            String baseK = Integer.toString( n, k );
            System.out.println( String.valueOf( baseK ).length() );
        }

        sc.close();
    }
}