#include<bits/stdc++.h>
using namespace std;

void solve() {
	long long x, n, d; cin >> x >> n >> d;
	if (gcd(x, d) != 1) {
	    cout << "inf" << '\n';
	    return;
	}
	if (x == 1) {
	    cout << -1 << '\n';
	    return;
	}
	cout << (x-2)/n*x+(x-1)*d << '\n';
}

int main() {
	int T; cin >> T;
	while (T--) solve();
}