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 Python (3.4.3) (judge verdict: Accepted)

def resolve_b():
    n, k = map(int, input().split())

    def Base_10_to_n(X, n): # 再帰処理
        if (int(X / n)):
            return Base_10_to_n(int(X / n), n) + str(X % n)
        return str(X % n)

    ans = Base_10_to_n(n, k)
    print(len(str(ans)))
resolve_b()