#define _CRT_SECURE_NO_WARNINGS
#define IO ios::sync_with_stdio(false);cin.tie(0);cout.tie(0) 
#include<unordered_map>
#include<unordered_set>
#include<bits/stdc++.h>
#include<array>
using namespace std;
typedef long long ll;
typedef pair<ll, ll>pi;
#define int ll
#define X first
#define Y second
#define fer(i,a,n) for(ll i=a;i<=n;i++)
#define ref(i,n,a) for(ll i=n;i>=a;i--)
#define endl '\n'
#define mem(a,x) memset(a,x,sizeof a)
#define ac IO;int t;cin>>t;while(t--)solve()
#define AC signed main(){IO;solve();}
#define NO {cout<<"No"<<endl;return;}
#define YES {cout<<"yes"<<endl;return;}
#define re(a) {cout<<a<<endl;return;}
#define all(v) v.begin(),v.end()
//ofstream fout("out.txt", ios::out);
//ifstream fin("in.txt", ios::in);
//#define cout fout
//#define cin fin
//--------------------瑞神神中神--------------------

inline int qdiv(int a, int b)
{
	return a / b + ((a - a / b * b) & 1);
}

int a, b, c;

int qmi(int a, int b)
{
	int ans = 1;
	while (b)
	{
		if (b & 1)ans *= a;
		a *= a;
		b >>= 1;
	}
	return ans;
}

void solve()
{
	cin >> a >> b >> c;
	int ans = 1e18, sum = 0, x = 1;
	while (x <= 2 * c)
	{
		int res = sum + qdiv(c, x) * b;
		sum += a;
		x <<= 1;
		ans = min(ans, res);
	}
	cout << ans << endl;
}

signed main()
{
	ac;
}