421 | Йо-йо

Java Solution:

import java.util.Scanner;
public class solution_3 {

    public static void main(String[] args){

        Scanner scn = new Scanner(System.in);
        double l = scn.nextInt(), k = scn.nextInt();        int counter = 0;
        l /= k;
        try {
            while (l > 1) {
                l /= k;                ++counter;            }
        } catch (Exception e){
            e.getMessage();        }

        System.out.print(counter);    }

}