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)

N, K = map(int, input().split())
#%%time
i = 0
ans = 0
while i <= 10**9:
    if N < K:
        ans = 1
        break
    elif N == K:
        ans = 2
        break
    elif K**i > N:
        ans =  i
        break
    else :
         i += 1 
print(ans)