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

inline int rd() {
	int x = 0;
	bool f = 0;
	char c = getchar();
	for (; !isdigit(c); c = getchar()) f |= (c == '-');
	for (; isdigit(c); c = getchar()) x = x * 10 + (c ^ 48);
	return f ? -x : x;
}

template<typename T>
inline bool getmax(T &a, T b) {return a < b ? (a = b, true) : false;}
template<typename T>
inline bool getmin(T &a, T b) {return a > b ? (a = b, true) : false;}

inline void work() {
	ll a = rd(), b = rd(), c = rd();
	ll ans = 9e18;
	for (int i = 0; i <= 30; ++i) 
		ans = min(ans, i * a + (c + (1 << i) - 1) / (1 << i) * b);
	printf("%lld\n", ans);
}

int main() {
	for (int t = rd(); t; --t) work();
	return 0;
}