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)

/* ex 3-3
    kas056*/
#include <stdio.h>
int main(void){
    int n , k ;
    // n,kの読み込み
    scanf("%d %d", &n, &k);

    //何乗したかのカウンターiとその時点の数値tを用意
    int i = 1;
    int t = k;

    //k進法の桁数はk^i>nとなるようなiに決まるので、そのiになるまでtにkを掛けていく
    while (t <= n){
        t *= k;
        i += 1;
    }
    //iを出力
    printf("%d",i);
    return 0;
}