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)

/*3.3 hightierra*/
#include <stdio.h>
#include <math.h>
 
int main(void){
    int N,K; //変数の定義
    scanf("%d %d",&N,&K); //入力
 
    int exp = 1; //指数を定義
 
    /*K^(exp-1)<=N<K^expのとき、NはK進法でexp桁*/
    while(pow((double)K,(double)exp)<=N){
      	exp++;
    }
    printf("%d\n",exp);
    return 0;
}