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 num, base; //整数num,進数base
    int dig = 0; //桁数dig

    scanf("%d %d",&num, &base); //num,base入力

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

    printf("%d\n",dig); //桁数digを出力

    return 0;
}