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)

// 課題3_3 AtCoder Beginner Contest 156 B - Digits
// nk777
 
#include <stdio.h>
 
int main(void){
    // 整数NのK進数のn,k、途中計算の値の格納n_cal、結果の格納result
    // 1の位分があるので初期設定はresult = 1(log_k(N)+1の1の部分)
    int n, k, n_cal, result = 1;
 
    // n,kを受け取る
    scanf("%d %d", &n, &k);

    // 最初の値を代入
    n_cal = n;

    while (n_cal >= k)
    {
        result++;
        n_cal = n_cal / k;
    }
    
    printf("%d\n", result);

    return 0;
}