typedef long long ll;
typedef long double ld;
#include <bits/stdc++.h>
using namespace std;

int main() {
    ll q;
    std::cin >> q;
    
    for (int i = 0; i < q; i++) {
        ll a,b,c;
        std::cin >> a>>b>>c;
        if(c==1){
            std::cout << -1 << std::endl;
            continue;
        }
        
        ll cnt = 0;
        while(a%c>0||a/c>0){
            if(a%c!=0)cnt++;
            if(a/c!=0)cnt++;
            if(a%c!=0&&a%c<=c-2&&a/c%c==1)cnt--;
            a/=c;
        }
        std::cout << cnt*b << std::endl;
    }
}