#include<iostream>
#include<map>
#include<vector>
#include <algorithm>
#include<math.h>
#include <iomanip>
#include<set>
#include <numeric>
using namespace std;


int main()
{
    int n;
    cin >> n;
    for (int i = 0; i < n; i++){
        long long n, k;
        cin >> n >> k;
        if (n <= k) cout << 1 << endl;
        else if (k == 1) cout << n - 1 << endl;
        else {
            for (int j = 2; j < 32; j++){
                if (pow(k, j) >= n){
                    cout << j << endl;
                    break;
                }
            }
        }
    }   
}