#include<iostream>
#include<cstdio>
#include<algorithm>
#include<queue>
#include<vector>
#include<cstring>
#include<cassert>
using namespace std;

int T;
struct HugeInt
{
    typedef unsigned long long ll;
    static const int BASE=100000000;
    static const int WIDTH=8;
    vector<int> s;
    HugeInt &clean()
    {
        while(!s.back()&&s.size()>1)
            s.pop_back();
        return *this;
    }
    HugeInt(ll num=0) {*this=num;}
    HugeInt(string s) {*this=s;}
    HugeInt &operator = (ll num)
    {
        s.clear();
        do{
            s.push_back(num%BASE);
            num/=BASE;
        } while(num>0);
        return *this;
    }
    HugeInt &operator=(const string &str)
    {
        s.clear();
        int x, len=(str.length()-1)/WIDTH+1;
        for(int i=0;i<len;i++)
        {
            int end=str.length()-i*WIDTH;
            int start=max(0,end-WIDTH);
            sscanf(str.substr(start,end-start).c_str(),"%d",&x);
            s.push_back(x);
        }
        return (*this).clean();
    }
    HugeInt operator + (const HugeInt &b)const{
        HugeInt c; c.s.clear();
        for(int i=0,g=0;;i++)
        {
            if(g==0&&i>=s.size()&&i>=b.s.size()) break;
            int x=g;
            if(i<s.size()) x+=s[i];
            if(i<b.s.size()) x+=b.s[i];
            c.s.push_back(x%BASE);
            g = x/BASE;
        }
        return c;
    }
    HugeInt operator - (const HugeInt &b)const{
        HugeInt c; c.s.clear();
        for(int i=0,g=0;;i++)
        {
            if(g==0&&i>=s.size()&&i>=b.s.size()) break;
            int x=s[i]+g;
            if(i<b.s.size()) x-=b.s[i];
            if(x<0) g=-1, x+=BASE; 
            else g=0;
            c.s.push_back(x);
        }
        return c.clean();
    }
    HugeInt operator * (const HugeInt &b)const{
        int i, j; ll g;
        vector<ll> v(s.size()+b.s.size(),0);
        HugeInt c; c.s.clear();
        for(i=0;i<s.size();i++)
            for(j=0;j<b.s.size();j++)
                v[i+j]+=ll(s[i])*b.s[j];
        for(i=0, g=0;;i++)
        {
            if(g==0&&i>=v.size()) break;
            ll x=v[i]+g;
            c.s.push_back(x%BASE);
            g=x/BASE;
        }
        return c.clean();
    }
    HugeInt operator / (const HugeInt &b)const{
        HugeInt c = *this;
        HugeInt m;
        for(int i=s.size()-1;i>=0;i--)
        {
            m = m*BASE+s[i];
            c.s[i] = bsearch(b,m);
            m -= b*c.s[i];
        }
        return c.clean();
    }
    HugeInt operator % (const HugeInt &b)const{
        HugeInt c = *this;
        HugeInt m;
        for(int i=s.size()-1;i>=0;i--)
        {
            m=m*BASE+s[i];
            c.s[i]=bsearch(b,m);
            m-=b*c.s[i];
        }
        return m;
    }
    int bsearch(const HugeInt &b, const HugeInt &m)const{
        int L=0, R=BASE-1, x;
        while(L<=R)
        {
            x=(L+R)>>1;
            if(b*x<=m)
            {
                if(b*(x+1)>m) return x; 
                else L=x+1;
            } 
            else R=x-1;
        }
    }
    HugeInt& operator -= (const HugeInt &b) {*this = *this-b; return *this;}
    bool operator < (const HugeInt &b)const{
        if(s.size()!=b.s.size()) return s.size()<b.s.size();
        for(int i=s.size()-1;i>=0;i--)
            if(s[i]!=b.s[i]) return s[i]<b.s[i];
        return false;
    }
    bool operator > (const HugeInt &b)const{return b<*this;}
    bool operator <= (const HugeInt &b)const{return !(b<*this);}
    bool operator == (const HugeInt &b)const{return !(b<*this)&&!(b>*this);}
}A, B, C, X, Y, D;
ostream& operator << (ostream &out, const HugeInt &x)
{
    out << x.s.back();
    for(int i=x.s.size()-2;i>=0;i--)
    {
        char buf[20];
        sprintf(buf,"%08d",x.s[i]);
        for(int j=0;j<strlen(buf);j++) out << buf[j];
    }
    return out;
}
istream& operator >> (istream &in, HugeInt &x)
{
    string s;
    if(!(in>>s)) return in;
    x=s; return in;
}
HugeInt min(HugeInt a, HugeInt b) {return a<=b?a:b;}
int main()
{
    // freopen("testdata.in","r",stdin);
    cin >> T;
    while(T--)
    {
        cin >> A >> B >> C >> X >> Y >> D;
        // cout << A << " " << B << " " << C << " " << X << " " << Y << " " << D << " " << '\n';
        HugeInt c1, c2, c3;
        if(D<=X) {cout << A << '\n'; continue;}
        if(D<=X+Y) c1=A*B+(D-X);
        else c1=A+B*Y+C*(D-X-Y);
        HugeInt cA, nA, left;
        cA=(D/X)*A;
        nA=D/X;
        left=D-nA*X; 
        if(nA*Y<left) c2 = cA+min(nA*Y*B+(left-nA*Y)*C, Y*B+(left-Y)*C);
        else if(Y<=left) c2 = cA+min(left*B, Y*B+(left-Y)*C);
        else c2 = cA+left*B;
        c2=min(c2,cA+A);
        HugeInt bD=X+Y, bC=A+B*Y, cAB, nAB;
        cAB=(D/bD)*bC;
        nAB=D/bD;
        left=D-D/bD*bD; 
        if(left<X) c3 = cAB+A-min(nAB*Y,X-left)*B; 
        else c3 = cAB+A+(left-X)*B;
        if(D>X+Y) c3 = min(c3,cAB+C*left);
        cout << min(c1,min(c2,c3)) << '\n';
    }
    return (0-0);
}