#include<bits/stdc++.h> using namespace std; #define int long long #define rep(i,n) for(int i=0;i<(n);i++) #define pb push_back #define all(v) (v).begin(),(v).end() #define fi first #define se second typedef vector<int>vint; typedef pair<int,int>pint; typedef vector<pint>vpint; template<typename A,typename B>inline void chmin(A &a,B b){if(a>b)a=b;} template<typename A,typename B>inline void chmax(A &a,B b){if(a<b)a=b;} signed main(){ int Q;cin>>Q; while(Q--){ int N,K; cin>>N>>K; if(K==1){ cout<<N-1<<endl; continue; } int sum=1; int p=1; for(int i=0;;i++){ if(sum>=N){ cout<<i<<endl; break; } p*=K; sum+=p; } } return 0; }