#include <iostream>
#include <vector>
using namespace std;
typedef long long ll;

ll solve(ll a,ll b,ll c){
    if(c==1) return -1;
    if(a<c) return b;
    if(a==c) return 2*b;
    ll r = a%c,k = a/c;
    ll cnt = (r!=0) + (k!=1);
    return cnt*b+solve(k,b,c);
}

int main(){
    int Q;
    cin >> Q;
    for(int i=0;i<Q;i++){
        ll a,b,c;
        cin >> a >> b >> c;
        cout << solve(a,b,c) << endl;
    }   
}