#include<bits/stdc++.h>
using namespace std;
#define inf INT_MAX
#define INF LLONG_MAX
#define ll long long
#define ull unsigned long long
#define M (int)(1e9+7)
#define P pair<int,int>
#define PLL pair<ll,ll>
#define FOR(i,m,n) for(int i=(int)m;i<(int)n;i++)
#define RFOR(i,m,n) for(int i=(int)m;i>=(int)n;i--)
#define rep(i,n) FOR(i,0,n)
#define rrep(i,n) RFOR(i,n,0)
#define all(a) a.begin(),a.end()
#define IN(a,n) rep(i,n){ cin>>a[i]; }
const int vx[4] = {0,1,0,-1};
const int vy[4] = {1,0,-1,0};
#define PI 3.14159265
#define F first
#define S second
#define PB push_back
#define EB emplace_back
#define int ll
#define vi vector<int>
#define IP pair<int,P>
#define PP pair<P,P>
#define Yes(f){cout<<(f?"Yes":"No")<<endl;}
#define YES(f){cout<<(f?"YES":"NO")<<endl;}


signed main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout<<fixed<<setprecision(20);

  int q;
  cin>>q;
  while(q--){
    int a,b,c;
    cin>>a>>b>>c;
    vi v;
    v.PB(a);
    while(a){
      if(a%c==0){
        a/=c;
      }else{
        a=(a/c)*c;
      }
      v.PB(a);
      //cout<<a<<endl;
      if(v.size()&&v[v.size()-1]==v[v.size()-1-1]){
        v.clear();
        break;
      }
    }
    reverse(all(v));
    int s=v.size()-1;
    if(v.size()>3&&c*2-2>=v[3]) s--;

    if(s==-1) cout<<-1<<endl;
    else cout<<b*s<<endl;
  }


}