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;
public class Main {
	public static void main(String[] args) {
		//入力の読み込み
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();  //整数Nの値
		int base = sc.nextInt();  //進数Kの値
		int i = 0;

		//基数の値^iごとに桁が増える
		while(Math.pow(base, i) <= n) {
			i++;
		}
		System.out.print(i);
	}
}