#include<bits/stdc++.h>
using namespace std;
using ll=long long;
using li=__int128;
using pi=pair<int,int>;
#define fi first
#define se second
const int N=2100;
const ll mod=1e18;
typedef vector<ll> inter;
inter read(){
	inter ans;
	string s;cin>>s;
	int len=s.size();
	for(int i=len-1;i>=0;i-=18){
		ll sum=0;
		for(int j=max(i-17,0);j<=i;++j) sum=sum*10+s[j]-'0';
		ans.push_back(sum);
	}
	return ans;
}
void print(inter a){
	int n=a.size()-1;
	printf("%lld",a.back());
	for(int i=n-1;i>=0;--i) printf("%018lld",a[i]);
}
bool operator<(inter a,inter b) {
	if(a.size()!=b.size()) return a.size()<b.size();
	int n=a.size()-1;
	for(int i=n;i>=0;--i)if(a[i]!=b[i]) return a[i]<b[i];
	return 0;
}
bool operator<=(inter a,inter b){
	if(a.size()!=b.size()) return a.size()<b.size();
	int n=a.size()-1;
	for(int i=n;i>=0;--i)if(a[i]!=b[i]) return a[i]<b[i];
	return 1;
}
bool operator>=(inter a,inter b){
	if(a.size()!=b.size()) return a.size()>b.size();
	int n=a.size()-1;
	for(int i=n;i>=0;--i)if(a[i]!=b[i]) return a[i]>b[i];
	return 1;
}
inter operator+(inter a,inter b) {
	int n=a.size()-1,m=b.size()-1;
	if(n<m) n=m,a.resize(n+1);
	for(int i=0;i<=m;++i) a[i]+=b[i];
	for(int i=0;i<n;++i)if(a[i]>=mod) ++a[i+1],a[i]-=mod;
	if(a[n]>=mod) a.push_back(1),a[n]-=mod;
	return a;
}
inter operator-(inter a,inter b){
	int n=a.size()-1,m=b.size()-1;
	for(int i=0;i<=m;++i) a[i]-=b[i];
	for(int i=0;i<=n;++i)if(a[i]<0) --a[i+1],a[i]+=mod;
	for(;n>=1 and !a[n];--n) a.pop_back();
	return a;
}
inter operator*(inter a,inter b){
	if(a==inter{0} or b==inter{0}) return inter{0};
	int n=a.size()-1,m=b.size()-1;
	static li tmp[200];
	memset(tmp,0,sizeof(li)*(n+m+2));
	for(int i=0;i<=n;++i)for(int j=0;j<=m;++j) tmp[i+j]+=(li)a[i]*b[j];
	for(int i=0;i<=n+m;++i)if(tmp[i]>=mod) tmp[i+1]+=tmp[i]/mod,tmp[i]%=mod;
	inter ans(tmp,tmp+n+m+1);
	if(tmp[n+m+1]) ans.push_back(tmp[n+m+1]);
	return ans;
}
__float128 estimate(inter&a){
	int n=a.size()-1;
	__float128 ans=0;
	for(int i=n;i>=0;--i) ans=ans*mod+a[i];
	return ans;
}
inter operator/(inter a,inter b){
	if(a<b) return inter{0};
	int n=a.size()-1,m=b.size()-1;
	inter ans(n-m+1),rem={0};
	for(int i=n;i>=0;--i){
		rem=rem*inter{0,1}+inter{a[i]};
		if(rem>=b){
			ans[i]=estimate(rem)/estimate(b);
			rem=rem-b*inter{ans[i]};
		}
	}
	while(ans.size()>1 && !ans.back()) ans.pop_back();
	return ans;
}
inter A,B,C,D,X,Y;
inter calc(inter d) {
    if(d<=X)return A;
    if(A<=B*X) {
        inter c=d/X,r=d-c*X;
       return c*A+min(c,B*r);
    }return A+(d-X)*B;
}
void solve() {
    A=read(),B=read(),C=read(),X=read(),Y=read(),D=read();
    if(D<=X+Y)print(calc(D));
    else if(A<=min(B,C)*X) {
        inter c=D/X,r=D-c*X;
        if(c.back()==0)print(A);
        inter as;
        if(Y>=r)as=c*A+r*B;
        else as=c*A+Y*B+(r-Y)*C;
        print(min(as,c*A+A));
    }else if(C*(Y+X)>=A+B*Y) {
        inter c=D/(X+Y),r=D-c*(X+Y);
        print(c*(A+B*Y)+calc(r));
    }else {
        inter c=D/(X+Y),r=D-c*(X+Y),as=min(calc(r),C*r);
        print(A+B*Y+(c-inter{1})*C*(X+Y)+as);
    }
    cout<<'\n';
}
int main() {
    #ifndef ONLINE_JUDGE
        freopen(".in","r",stdin);
        freopen(".out","w",stdout);
    #endif
    // ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
    int tt;cin>>tt;
    while(tt--)solve();
    return 0;
}