CF912E.Prime Gift

Opposite to Grisha's nice behavior, Oleg, though he has an entire year at his disposal, didn't manage to learn how to solve number theory problems in the past year. That's why instead of Ded Moroz he was visited by his teammate Andrew, who solemnly presented him with a set of n distinct prime numbers alongside with a simple task: Oleg is to find the k-th smallest integer, such that all its prime divisors are in this set.

与格里沙的良好表现相反，奥列格尽管有一整年的时间，却在过去一年中未能学会如何解决数论问题。因此，拜访他的并非圣诞老人（Дед Мороз），而是他的队友安德鲁——他庄重地送给奥列格一个由 n 个互不相同的素数组成的集合，并附上一道简单任务：奥列格需要找出第 k 小的正整数，使得该数的所有素因子均属于这个集合。

The first line contains a single integer n (1 ≤ n ≤ 16).

The next line lists n distinct prime numbers _p_1, _p_2, ..., p__n (2 ≤ p__i ≤ 100) in ascending order.

The last line gives a single integer k (1 ≤ k). It is guaranteed that the k-th smallest integer such that all its prime divisors are in this set does not exceed 1018.

第一行包含一个整数 $n$（$1 \leq n \leq 16$）。

第二行按升序列出 $n$ 个互不相同的质数 $p_1,\,p_2,\,...,\,p_n$（$2 \leq p_i \leq 100$）。

最后一行给出一个整数 $k$（$1 \leq k$）。保证满足“所有质因数均属于该集合”的第 $k$ 小的正整数不超过 $10^{18}$。

Print a single line featuring the k-th smallest integer. It's guaranteed that the answer doesn't exceed 1018.

输出一行，包含第 k 小的整数。保证答案不超过 $10^{18}$。

The list of numbers with all prime divisors inside {2, 3, 5} begins as follows:

(1, 2, 3, 4, 5, 6, 8, ...)

The seventh number in this list (1-indexed) is eight.

所有素因子均属于集合 $\{2,\,3,\,5\}$ 的正整数序列如下所示：

$(1,\,2,\,3,\,4,\,5,\,6,\,8,\,\ldots)$

该序列中第 $7$ 个数（从 $1$ 开始计数）是 $8$。