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
    potter0723sw  */

//方針：NをKで何回も割って商が0になるまでの割る回数をカウントする

#include <stdio.h>

int main(void) {
	int number,ary,answer;
	scanf("%d %d", &number, &ary);
	answer = 1;//最後に2桁増えることを考慮して1からスタート
	while(number >= ary){//numberがaryより小さくなったら割るのを終わる
		number = number / ary;
		answer += 1;
	}
	printf("%d\n",answer);
	return 0;
}