def solve():
    input_str = input("")
    inp = [int(num) for num in input_str.split()]
    A = inp[0]
    B = inp[1]
    C = inp[2]
    X = inp[3]
    Y = inp[4]
    D = inp[5]
    if D <= X:
        print(A)
        return
    elif D<=X+Y:
        ans1 = 0
        DD = D
        t = int(DD/X)
        ans1 += A*t
        DD -= t*X
        ans1+=min(A,DD*B)
        ans2 = A+(D-X)*B
        print(min(ans1,ans2))
        return
    ans1 = A+Y*B+C*(D-X-Y)
    ans2 = 0
    DD = D
    t = int(DD/X)
    ans2 += A*t
    DD -= t*X
    if DD > Y:
        ans2 += min(A,Y*B+(D-Y)*C)
    else:
        ans2 += min(A,DD*B)
    
    ans3 = 0
    DD = D
    t = int(DD/(X+Y))
    ans3 += A*t + t*B*Y
    DD -= t*(X+Y)
    if DD<=X:
        ans3 += A - (X-DD)*B
    else:
        ans3 += min(A+(DD-X)*B,DD*C)

    print(min(ans1,min(ans2,ans3)))

times = int(input(""))

for i in range(times):
    solve()

answer.code:3:1: error: ‘def’ does not name a type
    3 | def solve():
      | ^~~