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
//TKC001
 
#include<stdio.h>
#include<math.h>
 
int main(void){
	//1.exactを真数, baseを底として対数を求める。
    double exact, base, logkn;
    int digits;
 
    scanf("%lf", &exact);
    scanf("%lf", &base);
 
    logkn = log(exact) / log(base);
	//1.ここまで
 
	//2.logknの小数点を切り捨て
	digits = logkn;
 
	//3.桁数を表示
    printf("%d", digits+1);
 
    return 0;
 
}