#include<bits/stdc++.h>
using namespace std;
#define int long long
const int maxn=1e5+5;
void solve(){
    int p,a,b,q,c,d,m,t;
    cin>>p>>a>>b;
    cin>>q>>c>>d;
    cin>>m>>t;
    if(m<q){
        cout<<m<<endl;
        return ;
    }
    int bg,t1,ll;
    while(1){
        bg=m/p;//当前这些钱能买bg袋
        t1=(a+c)*bg+b+d;//买一次的时间
        ll=ceil(1.00*(p*(bg+1)-m)/((q-p)*bg));//需要买几次才能多买一袋
        if(ll*t1>t){
            m+=t/t1*(q-p)*bg;//先能买几轮就买几轮
            t-=t/t1*t1;
            break;//不够买ll轮
        }
        t-=ll*t1;
        m+=ll*(q-p)*bg;
    }
    //跳出来之后得看一下还能买几个面粉
    // int lst=(t-b-d)/(a+c);
    // m+=(q-p)*lst;
    int l=0,r=t+1;
    while(l+1!=r){
        int mid=l+r>>1;
        if(a*mid+b+c*mid+d<=t)l=mid;
        else r=mid;
    }
    m+=(q-p)*l;
    cout<<m<<endl;      
}
signed main(){
    int ques;
    cin>>ques;
    while(ques--)solve();
    return 0;
}