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 Go (1.6) (judge verdict: Accepted)

package main

import (
  "fmt"
)

func main() {
  var n,k int
  fmt.Scan(&n)
  fmt.Scan(&k)

  baseNum := k
  tmpNum := n
  conversionNum := "" // 変換後の値格納用　11進以上はアルファベットのため、文字列で扱う必要がある

  for digitNum := 1;; {
      remainder := tmpNum%baseNum
      if remainder >= 10 {
          conversionNum = string('A' + (remainder-10)) + conversionNum
      } else {
          conversionNum = string('0' + remainder) + conversionNum
      }
      tmpNum = tmpNum/baseNum
      if tmpNum == 0 {
          break
      }
      digitNum *= 10
  }
  fmt.Println(len(conversionNum))
}