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: Accepted)

#![allow(
    non_snake_case,
    unused_variables,
    unused_assignments,
    unused_mut,
    dead_code
)]
//use proconio::fastout;
use proconio::input;
use proconio::marker::Chars;
//use proconio::marker::Usize1;
//use std::collections::HashSet;
// use std::cmp::*;
//use std::collections::VecDeque;

fn main() {
    input! {
      N:usize,K:usize
    }
    //    let mut ans = 0;
    let mut t = 1;
    if N == 1 {
        println!("1");
        return;
    }
    for i in 1..31 {
        t *= K;
        if N < t {
            println!("{}", i);
            return;
        }
    }
}