#include <bits/stdc++.h>
using namespace std;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    int q;
    cin >> q;
    while (q--) {
        int n, k;
        cin >> n >> k;
        if (k == 1) {
            cout << n - 1 << '\n';
            continue;
        }
        long long cur = 1;
        int cnt = 0;
        while (cur < n) {
            cur *= k;
            cnt++;
        }
        cout << cnt << '\n';
    }
}