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)

use std::io::{self, BufRead};

fn main() {
    let stdin = io::stdin();
    let mut lines = stdin.lock().lines();
    let nk = lines.next().unwrap().unwrap();
    let mut nk = nk.split_whitespace();
    let n: i32 = nk.next().unwrap().parse().unwrap();
    let k: i32 = nk.next().unwrap().parse().unwrap();

    let mut pow = k;
    let mut ans = 1;
    while n >= pow {
        pow *= k;
        ans += 1;
    }

    println!("{}", ans);
}