#include<iostream>
#include<unordered_map>
#include<vector>
#include<algorithm>
#include<string>
#include<math.h>
#include<map>
#include<set>
#include<string.h>
#include<iomanip>
#include<queue>
using namespace std;
const int N = 200015;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> PII;
//int mod = 998244353;

int main()
{
	int t;
	cin >> t;
	while (t--)
	{
		ull n, x, t;
		cin >> n >> x >> t;
		ull z = n*t+ n * t;
		ull ans = z + z + max(ull(0), x - z + t + t);
		cout << ans << endl;
	}

}