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)

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

int main(){
    int N,K;
    scanf("%d%d", &N, &K);
    
    int x,y;
    int ans=0;
    int flag=0;
   
    x = -1;
    while( flag == 0 ){
        x += 1;
        y = N / pow(K, x);
        if( y < 1 ) flag = 1;
        else ans = x+1;
    }

    printf("%d\n", ans);
    return 0;
}