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)

/* kadai3_3
   Saikyo_Kazune
*/
#include <stdio.h>
int pow(int K,int L){
    if(L==0){
        return 1;
    }
    else if(L%2==1){
        return K*pow(K,L-1);
    }
    else{
        return pow(K,L/2)*pow(K,L/2);
    }
}

int main(void){
   //int型　N,K,桁数ようにLを宣言
   int N,K,L=1;
   scanf("%d %d",&N,&K);
   while(N/pow(K,L)!=0){
       L++;
   }
   printf("%d\n",L);

    return 0;
}