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 Haskell (GHC 7.10.3) (judge verdict: Accepted)

import Data.List.Split

toInt :: String -> Int
toInt = read ::String -> Int

countDigits :: Int -> Int -> Int
countDigits n k 
  | n == 0 = 0
  | otherwise = 1 + countDigits (div n k) k

main = do
  s <- getLine
  let l = splitOn " " s
  let n = toInt (l!!0)
  let k = toInt (l!!1)
  putStrLn $ show $ countDigits n k