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 Rust (1.15.1) (judge verdict: Accepted)

fn main() {
    let mut buf = String::new();
    std::io::stdin().read_line(&mut buf).unwrap();
    let mut it = buf.split_whitespace().map(|x| x.parse::<i64>().unwrap());
    let mut x = it.next().unwrap();
    let k = it.next().unwrap();
    let mut exp = 0;
    while x > 0 {
        if x > 0 {
            exp += 1;
            x = x / k;
        } else {
            break;
        }
    }
    println!("{}", exp);
}