fn main() {
    let mut q = String::new();
    std::io::stdin().read_line(&mut q).ok();
    let q: usize = q.trim().parse().unwrap();

    for _ in 0..q {
        let mut s = String::new();
        std::io::stdin().read_line(&mut s).ok();
        let mut itr = s.trim().split_ascii_whitespace();
        let n: usize = itr.next().unwrap().parse().unwrap();
        let k: usize = itr.next().unwrap().parse().unwrap();

        if k == 1 {
            println!("{}", n - 1);
            continue;
        } else {
            let mut cnt: usize = 1;
            let mut p: usize = k;
            while p < n {
                p *= k;
                cnt += 1;
            }
            println!("{}", cnt);
        }
    }
}