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;

fn main() {
	let mut buf = String::new();
	io::stdin().read_line(&mut buf).expect("");
	let mut iter = buf.split_whitespace();
	let mut n:u64 = match iter.next().unwrap().parse() {
		Ok(n) => n,
		Err(_) => panic!(""),
	};
	let k:u64 = match iter.next().unwrap().parse() {
		Ok(n) => n,
		Err(_) => panic!(""),
	};
	let mut v: Vec<u64> = Vec::new();
	while n != 0 {
		v.push(n%k);
		n = n/k;
	}
	println!("{}", v.len());
}