import math
for _ in range(int(input())):
    a = list(input().split(' '))
    A = int(a[0])
    B = int(a[1])
    C = int(a[2])
    X = int(a[3])
    Y = int(a[4])
    D = int(a[5])
    if D<=X:
        print(A)
        continue
    def cal(dis):
        if(dis == 0):
            return 0
        ret = A
        dis -= X
        if dis <= 0:
            return ret
        if dis <= Y:
            ret += B * dis
        else:
            dis -= Y
            ret += Y*B + C * dis
        return ret
    
    ans = int(10 ** 4399)
    # case 1:
    case1_times = D // X
    mo = D % X
    if(mo > 0):
        case1_times += 1
    case1_val = case1_times * A
    
    ans = min(ans, case1_val)

    # case 2:
    case2_rest = D - (case1_times - 1) * X
    case2_times = case1_times - 1
    case2_val = (case2_times-1) * A + cal(case2_rest+X)
    ans = min(ans, case2_val)

    # case 3:
    case3_times = D // (X + Y)
    mo = D % (X + Y)
    if mo:
        case3_times += 1

    fuyu = (X + Y) * case3_times - D
    case3_val = (A + B * Y) * case3_times
    case3_val -= min(fuyu, Y) * B
    ans = min(ans, case3_val)
    
    # case 4:
    case4_times = case3_times - 1
    case4_res = D - (X + Y) * case4_times
    case4_val = (case4_times - 1) * (A + B * Y) + cal(X + Y + case4_res)
    # print(case4_times, case4_res, case4_val)
    if case4_times > 0:
        ans = min(ans, case4_val)
    
    case4_times = case4_times - 1
    case4_res = D - (X + Y) * case4_times
    case4_val = (case4_times - 1) * (A + B * Y) + cal(X + Y + case4_res)
    if case4_times > 0:
        ans = min(ans, case4_val)

    # case 5:
    case5_val = cal(D)
    ans=min(ans, case5_val)
    
    # Case 8: (exgcd?)
    a=(D+X+Y-1)//(X+Y)
    if a*X<=D:
        b=D-a*X
        case8_val=a*A+b*B
        ans = min(ans,case8_val)
    else:
        case8_val = 0


    # case 6:
    D -= X;
    case6_val = A
    if D > 0:
        case6_times = D // (X + Y)
        mo = D % (X + Y)
        if mo:
            case6_times += 1

        case6_times = case6_times - 1
        case6_rest = D - (X + Y) * case6_times
        case6_val += case6_times * (A + B * Y) + cal(case6_rest)
        ans = min(ans, case6_val)
    else:
        case6_val = ans
    
    # case 7:
    D -= X;
    case7_val = 2 * A
    if D > 0:
        case7_times = D // (X + Y)
        mo = D % (X + Y)
        if mo:
            case7_times += 1

        case7_times = case7_times - 1
        case7_rest = D - (X + Y) * case7_times
        case7_val += case7_times * (A + B * Y) + cal(case7_rest)
        ans = min(ans, case7_val)
    else:
        case7_val = ans

    # print([case1_val, case2_val, case3_val, case4_val, case5_val, case6_val])
    print(ans)

answer.code:28:7: error: invalid preprocessing directive #case
   28 |     # case 1:
      |       ^~~~
answer.code:37:7: error: invalid preprocessing directive #case
   37 |     # case 2:
      |       ^~~~
answer.code:43:7: error: invalid preprocessing directive #case
   43 |     # case 3:
      |       ^~~~
answer.code:54:7: error: invalid preprocessing directive #case
   54 |     # case 4:
      |       ^~~~
answer.code:58:7: error: invalid preprocessing directive #print
   58 |     # print(case4_times, case4_res, case4_val)
      |       ^~~~~
answer.code:68:7: error: invalid preprocessing directive #case
   68 |     # case 5:
      |       ^~~~
answer.code:72:7: error: invalid preprocessing directive #Case
   72 |     # Case 8: (exgcd?)
      |       ^~~~
answer.code:82:7: error: invalid preprocessing directive #case
   82 |     # case 6:
      |       ^~~~
answer.code:98:7: error: invalid preprocessing directive #case
   98 |     # case 7:
      |       ^~~~
answer.code:114:7: error: invalid preprocessing directive #print
  114 |     # print([case1_val, case2_val, case3_val, case4_val, case5_val, case6_val])
      |       ^~~~~
answer.code:1:1: error: ‘import’ does not name a type
    1 | import math
      | ^~~~~~
answer.code:1:1: note: C++20 ‘import’ only available with ‘-fmodules-ts’, which is not yet enabled with ‘-std=c++20’
answer.code:84:5: error: ‘case6_val’ does not name a type
   84 |     case6_val = A
      |     ^~~~~~~~~
answer.code:100:5: error: ‘case7_val’ does not name a type
  100 |     case7_val = 2 * A
      |     ^~~~~~~~~