#include <iostream>
#include <vector>
#include <math.h>
using namespace std;
using ll = long long;
vector<int> ans;
void solve(ll n , ll k){
	if(k == 1){
		ans.push_back(n - 1);
		return;
	}
	if(k >= 2){
		n -= 1;
		int res = 0;
		while(n > 0){
			n /= k;
			res++;
		}
		ans.push_back(res);
		return;
	}
}
int main(){
	int q;
	cin >> q;
	while(q--){
		ll n , k;
		cin >> n >> k;
		solve(n , k);
	}
	for(int i = 0; i < ans.size(); i++){
		cout << ans[i] << endl;
	}
	return 0;
}