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: Wrong Answer)

/*  ex3_3
    supercomputerjoi    */

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

int main(void){

    int num, base;
    int digits;

    // input N
    scanf("%d", &num);

    // input K
    scanf("%d", &base);

    // calculate log_K^N = logN / logK
    digits = (int)ceil(log(num) / log(base));

    //print digits
    printf("%d\n", digits);

    return 0;
}