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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
class Program {
  static void Main(string[] args) {
    string[] input = Console.ReadLine().Split(' ');
    int n = int.Parse(input[0]);
    int k = int.Parse(input[1]);
    double x = Math.Log(n, k);
    int i;
    for (i=0; i<=x; i++);
    Console.WriteLine(i);
  }
}