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_2
   moka223711 */

#include <stdio.h>

int main(void){
	int N, K, i = 1;
	scanf("%d %d", &N, &K);

	// NがK^i以上のとき、K進法はi桁で表せる
	// NをKで割り続けて何回割れるかをiでカウントする
	while(N >= K){
		N /= K;
		i++;
	}

	printf("%d", i);

	return 0;
}