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

int main() {
    int q;
    cin >> q;
    
    for (int _ = 0; _ < q; _++) {
        int64_t n, k;
        cin >> n >> k;
        
        int64_t ans = 0;
        for (int64_t tmp = 1; tmp < n; tmp *= k) {
            ans++;
        }
        cout << ans << endl;
    }
    
    return 0;
}