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 (Clang 3.8.0) (judge verdict: Wrong Answer)

#include <stdio.h>
#include <math.h>
int convert(int x, int n){
    int y=0, i=0, z;
    while(x > 0){
        z = x%n;
        y += z*pow(10, i);
        x = x/n;
        i++;
    }
    return y;
}




int str_length(const char*s)
{
  int len=0;

  while (*s++)
    len++;
  return len;
}

int main(void)
{
  char str[128];
  int s,i,k;
  scanf("%s",str);
  scanf("%d",&s);
    scanf("%d",&i);
    (k="%d\n", convert(s, i));
  
 printf("%d\n",str_length(str)*2);
 
  return 0;
}