#include <bits/stdc++.h>
#define int long long
using namespace std;
const int MOD = 1000000007;
using Graph = vector<vector<int>>;

signed main() {
  int Q;
  cin >> Q;
  
  for( int i = 0; i < Q; i++ ){
    int N, K;
    cin >> N >> K;
    if( K == 1 ){
      cout << N-1 << endl;
      continue;
    }
    int now = 1;
    int cnt = 0;
    while( now < N ){
      now *= K;
      cnt++;
    }
    cout << cnt << endl;
  }
}