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
	kanon */

#include <stdio.h>

int main(void)
{

    //与えられる値を入れる変数を宣言
    int num, base;

    //変数に値を入力する
    scanf("%d %d", &num, &base);

    //logを用いてNをK進法で表したときの桁数を計算する
    int answer=log(num)/log(base)+1;

    printf("%d\n",answer);

    return 0;
}