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)

/* ex3_3
        fmuacshai */
 
#include<stdio.h>
//math関数を導入
#include<math.h>
int main(void){
    //整数number、進数k、桁数mを整数定義
    int number,base_number,digits;
    //numberの入力
    scanf("%d",&number);
    //kの入力
    scanf("%d",&base_number);
    //mの初期設定
    digits=1;
    //(m+1)桁の最小の数字以上であるかチェック
    while(number>=pow(base_number,digits)){
        digits=digits+1;
    }
    //求めた桁数mの出力
    printf("%d\n",digits);
    return 0;
}