#include <bits/stdc++.h>
 
using namespace std;
 
#define lli long long int
#define REP(i,s,n) for(int i=s;i<n;i++)
#define MOD 1000000007
#define NUM 2520
#define INF (1LL<<50)
#define DEBUG 0
#define mp(a,b) make_pair(a,b)
#define SORT(V) sort(V.begin(),V.end())

lli b,c;

lli calc(lli a){
	lli next=0;

	if(c==1)return -1;

	while(1){
		if(DEBUG)cout<<a<<endl;
		if(a<c){
			next+=b;
			break;
		}
		if(a<=2*(c-1)){
			next+= (2*b);
			break;
		}
		next+=b;
		if(a%c!=0)next+=b;
		a /= c;
	}

	return next;
}
void solve(){
	lli a;
	cin>>a>>b>>c;

	/*逆からやるとよさそう*/
	cout<<calc(a)<<endl;
}

signed main(){

	lli q;
	cin>>q;

	REP(i,0,q)solve();

	return 0;
}