#define _USE_MATH_DEFINES
#include <cstdio>
#include <iostream>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <algorithm>
#include <cmath>
#include <complex>
#include <string>
#include <vector>
#include <array>
#include <list>
#include <queue>
#include <stack>
#include <set>
#include <map>
#include <bitset>
#include <numeric>
#include <limits>
#include <climits>
#include <cfloat>
#include <functional>
#include <iterator>
#include <memory>
#include <regex>
using namespace std;

int main()
{
    int q;
    cin >> q;
    while(--q >= 0){
        int a, b, c;
        cin >> a >> b >> c;
        if(c == 1){
            cout << (a * (long long)b) << endl;
            continue;
        }

        set<int> s;
        queue<int> q;
        s.insert(a);
        q.push(a);

        long long ans = 0;
        while(*s.begin() != 0){
            ans += b;
            int n = q.size();
            while(--n >= 0){
                int x = q.front();
                q.pop();

                vector<int> v = {x / c * c};
                if(x % c == 0)
                    v.push_back(x / c);
                if(c - 1 <= x)
                    v.push_back(x - (c - 1));

                for(int y : v){
                    if(s.find(y) == s.end()){
                        s.insert(y);
                        q.push(y);
                    }
                }
            }
        }
        cout << ans << endl;
    }

    return 0;
}