#include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<bitset>
#include<set>
#include<map>
#include<stack>
#include<queue>
#include<deque>
#include<list>
#include<iomanip>
#include<cmath>
#include<cstring>
#include<functional>
using namespace std;

#define repr(i, a, b) for (int i = (int)(a); i < (int)(b); i++)
#define rep(i, n) repr(i, 0, n)
#define INF 2e9
#define MOD 1000000007
//#define MOD 998244353
#define LINF (long long)4e18
#define jck 3.141592

using ll = long long;
using Pi = pair<int,int>;
using Pl = pair<ll,ll>;

int main(){
   int Q; cin >> Q;
   while(Q--){
       int N,K; cin >> N >> K;
       int ans = 0;
       if(K == 1) ans = N-1;
       else{
           ll tmp = 1;
           while(true){
               if(tmp >= N) break;
               tmp *= K;
               ans++;
           }
       }
       cout << ans << endl;
   }

}