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
   kohei_suzuki */

#include <stdio.h>
#include <math.h>

int main(void){
    int n, k; //整数n,進数k
    int m = 0; //桁数m

    scanf("%d %d",&n, &k); //n.kの入力

    while(n >= pow(k,m)){ //nとk^mを比較して桁数を求める
        m  += 1; //mを1ずつ増やして繰り返し比較する
    }

    printf("%d\n",m); //桁数mを出力

    return 0;
}