for _ in range(int(input())):
    a, b, c, x, y, d = map(int, input().split())
    def calc(gap):
        if gap == 0:
            return 0
        if gap <= x:
            return a
        res = a + (gap - x) * b
        res = min(res, (gap + x - 1) // x * a)
        res = min(res, gap // x * a + gap % x * b)
        return res
    
    
    ans = -1
    if d <= x + y:
        ans = calc(d)
    else:
        ans = a + y * b + (d - x - y) * c
        ans = min(ans, (d + x - 1) // x * a)
        ans = min(ans, d // x * a + min(d % x, y) * b + max(d % x - y, 0) * c)
        ans = min(ans, d // x * a + d % x * b)
        ans = min(ans, d // (x + y) * (a + y * b) + (
                  ((d % (x + y) - x) * b + a) if d % (x + y) >= x 
                  else (a - min(x - d % (x + y), d // (x + y) * y) * b)
                ))
        ans = min(ans, d // (x + y) * (a + y * b) + d % (x + y) * c)

    print(ans)

answer.code:1:1: error: expected unqualified-id before ‘for’
    1 | for _ in range(int(input())):
      | ^~~