CF1836B Astrophysicists

 

/*
5
3 3 100
2 1 14
91 2 13
36 16 6
73 8 22

100
0
26
72
176

*/

/*

*/
#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cmath>
#include<string.h>
//#include<queue>
//#include<vector>
//#include<bits/stdc++.h>
#define ll long long
#define ddd printf("-----------------------\n");
using namespace std;
const int maxn=1e1 +10;
const int mod=998244353;
const int inf=0x3f3f3f3f;

ll n,g,k;

int main()
{
    ios::sync_with_stdio(false);
    int T;cin>>T;
    while(T--)
    {
        cin>>n>>k>>g;
        ll t=max(0ll,k*g-(n-1)*((g-1)/2));
        if(t%g>=((g+1)/2)) cout<<(k-(t+g-1)/g)*g<<'\n';
        else cout<<(k-t/g)*g<<'\n';
    }

    return 0;
}