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 (GCC 5.4.1) (judge verdict: Accepted)

#include <stdio.h>

int main (void){
  
  int N,K;
  scanf("%d %d",&N,&K);
  int n = 0,a = 1,ans;
  
  while(1){
    if(a <= N){
      a *= K;
      n++;
    }
    if(a >  N){
      ans = n;
      break;
    }
  }
  
  printf("%d\n",ans);
  return 0;
}