fn main() {
    let mut q = String::new();
    std::io::stdin().read_line(&mut q).ok();
    let q = q.trim().parse::<usize>().unwrap();
    for _ in 0..q {
        let mut line = String::new();
        std::io::stdin().read_line(&mut line).ok();
        let mut line = line.split_whitespace();
        let mut n: i64 = line.next().unwrap().parse().unwrap();
        let k: i64 = line.next().unwrap().parse().unwrap();
        if k == 1 {
            println!("{}", n-1);
            continue;
        }
        let mut ans = 0;
        while n > 0 {
            n /= k;
            ans += 1;
            if n == k {
                ans += 1;
                break;
            }
        }
        println!("{}", ans);
    }
}