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 (1.42.0) (judge verdict: Wrong Answer)

fn input_pair<T: std::str::FromStr + Copy> () -> (T, T) {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).unwrap();
    let arr: Vec<_> = s.trim().split_whitespace().flat_map(str::parse).collect();
    (arr[0], arr[1])
}

fn main() {
    let (n, k) = input_pair::<usize>();
    let mut a = n;
    let mut r = 1;
    loop {
        let b = a % k;
        a /= k;
        r += 1;
        if a <= 1 {
            if b != 0 {
                r -= 1;
            }
            break;
        }
    }
    println!("{}", r);
}