#include<iostream>
#define ll long long
using namespace std;

ll a,b,c;

ll up_div(ll i,ll j){
    ll num=i/j;
    if(i%j) num++;
    return num;
}

void sol(){
    ll num=1,cnt=0;
    while(a*cnt+b*up_div(c,num)>a*(cnt+1)+b*up_div(c,num*2)) num*=2,cnt++;
    cout<<a*cnt+b*up_div(c,num)<<"\n";
    return;
}

int main(){
    ll T; cin>>T;
    while(T--){
        cin>>a>>b>>c;
        sol();
    }
}